Looking at buying a 69/70 GT500. What I want to know is what would be good improvements/upgrades to the car, especially handling, ride and horsepower. I am not looking for a concours level car, so restoration is not my goal. I want the "look" of the 69, but with any improvements that can be made without completely wrecking the car. Things like shocks, stance, coaxing more HP out of the motor. Thoughts? Suggestions?
Brian, depends on how you intend on using the car and what objectives are. My 70 GT500 was my daily driver for 7 years.
As a former dealership mechanic, i'll say living with a 69/70 GT500 is a challenge.
Do you intend to drive long distances, urban driving, drag race, parades, cars/coffee, or what. Hot weather or not
Before anything, cooling system, brakes, tires, fuel hoses and front suspension need to be verified and optimized.
Next tune quality (carb, timing).
Then mods can be considered and will depend on budget, tastes, intended use, etc. mild to wild
Thanks AJ, good answer to an overly broad question. This will be my weekend car for car meets, shows and local runs. No big distance, but since I live in Vegas, lots of hot weather driving. No racing, but fun local hot rodding around the valley. I recently sold my 72 De Tomaso Pantera, and that was definitely a challenge, thankfully everything that really HAD to be done to the car was already done. So I have some familiarity with owning a vintage car. I just really want to maximize performance and handling, not afraid to own a "not 100% original" car.
Hard to say which mods without knowing the condition and specifics of the particular car. Then go from there
Quote from: aj on November 25, 2025, 10:13:54 PMBrian, depends on how you intend on using the car and what objectives are. My 70 GT500 was my daily driver for 7 years.
As a former dealership mechanic, i'll say living with a 69/70 GT500 is a challenge.
Do you intend to drive long distances, urban driving, drag race, parades, cars/coffee, or what. Hot weather or not
Before anything, cooling system, brakes, tires, fuel hoses and front suspension need to be verified and optimized.
Next tune quality (carb, timing).
Then mods can be considered and will depend on budget, tastes, intended use, etc. mild to wild
Yes, this is an understatement.
The entire history of modifications is available and that fills volumes.
As Commander Scott once said, "you remind me of the man who demanded to be taught the knowledge of the world while standing on one foot".
Where to begin? Pick a spot but someone needs to set some limits.
Quote from: aj on November 26, 2025, 08:02:26 AMHard to say which mods without knowing the condition and specifics of the particular car. Then go from there
Roger that
Quote from: shelbydoug on November 26, 2025, 08:22:44 AMQuote from: aj on November 25, 2025, 10:13:54 PMBrian, depends on how you intend on using the car and what objectives are. My 70 GT500 was my daily driver for 7 years.
As a former dealership mechanic, i'll say living with a 69/70 GT500 is a challenge.
Do you intend to drive long distances, urban driving, drag race, parades, cars/coffee, or what. Hot weather or not
Before anything, cooling system, brakes, tires, fuel hoses and front suspension need to be verified and optimized.
Next tune quality (carb, timing).
Then mods can be considered and will depend on budget, tastes, intended use, etc. mild to wild
Yes, this is an understatement.
The entire history of modifications is available and that fills volumes.
As Commander Scott once said, "you remind me of the man who demanded to be taught the knowledge of the world while standing on one foot".
Where to begin? Pick a spot but someone needs to set some limits.
"Limits"?
Quote from: Brian350 on November 26, 2025, 01:29:49 PMQuote from: shelbydoug on November 26, 2025, 08:22:44 AMQuote from: aj on November 25, 2025, 10:13:54 PMBrian, depends on how you intend on using the car and what objectives are. My 70 GT500 was my daily driver for 7 years.
As a former dealership mechanic, i'll say living with a 69/70 GT500 is a challenge.
Do you intend to drive long distances, urban driving, drag race, parades, cars/coffee, or what. Hot weather or not
Before anything, cooling system, brakes, tires, fuel hoses and front suspension need to be verified and optimized.
Next tune quality (carb, timing).
Then mods can be considered and will depend on budget, tastes, intended use, etc. mild to wild
Yes, this is an understatement.
The entire history of modifications is available and that fills volumes.
As Commander Scott once said, "you remind me of the man who demanded to be taught the knowledge of the world while standing on one foot".
Where to begin? Pick a spot but someone needs to set some limits.
"Limits"?
I would think so, yes. There are literally volumes of modifications available. "A man has got to know his limits"- Dirty Harry.
Having owned a 69 Big Block, I can offer some areas that I focused on:
Engine health - Especially in Vegas, cooling system 100%
Engine mods - I did a cam upgrade to make it a little happier mid-range. Headers and better exhaust, but still stock-ish. Maybe look into the throttle-body EFI so no vapor-locking and better running? Hides under the air cleaner for a good look.
Brakes - YES!!!! Best you can put inside the `15" wheels
Better shocks and sway bar connections. Connect it better to the road.
Front suspension & steering - New & Tight!
Quote from: Cobrask8 on November 26, 2025, 05:25:23 PMHaving owned a 69 Big Block, I can offer some areas that I focused on:
Engine health - Especially in Vegas, cooling system 100%
Engine mods - I did a cam upgrade to make it a little happier mid-range. Headers and better exhaust, but still stock-ish. Maybe look into the throttle-body EFI so no vapor-locking and better running? Hides under the air cleaner for a good look.
Brakes - YES!!!! Best you can put inside the `15" wheels
Better shocks and sway bar connections. Connect it better to the road.
Front suspension & steering - New & Tight!
Thanks!!
Quote from: Cobrask8 on November 26, 2025, 05:25:23 PMHaving owned a 69 Big Block, I can offer some areas that I focused on:
Engine health - Especially in Vegas, cooling system 100%
Engine mods - I did a cam upgrade to make it a little happier mid-range. Headers and better exhaust, but still stock-ish. Maybe look into the throttle-body EFI so no vapor-locking and better running? Hides under the air cleaner for a good look.
Brakes - YES!!!! Best you can put inside the `15" wheels
Better shocks and sway bar connections. Connect it better to the road.
Front suspension & steering - New & Tight!
Are you referring to my 428 SCJ on the cam upgrade?
First off if I was looking for what you are I'd buy a Gt350 4 speed. They are cheaper than a 500 and gives you more $$$ for upgrades. Why a 350? well you mentioned handling. Better handling cars to start with. MUCH easier to work on. I own a 68 Gt500, a 69 Mach1 R code and a 70 Gt350 vert. So take you savings and buy a Paxton and a Holley on the 351W and you have your horsepower. Want more? well there are nice aluminum heads to choose from. Add a 5 speed. Lots of suspension upgrades available to choose from. to buy a 500 and modify it for "handling and power" when you will always have a more balanced car with the Gt350 and adding the Paxton could give you the power you need might be a way for you to go. Also with the price difference you might even get yourself a nice crate engine to start with if you want more plug and play and keep the original engine off to the side. Good luck on your endeavor.
Excellent question and a very wise decision to enjoy your car
We first went through the engine with a stock rebuild bearings rungs etc. and valve job.
Only change was that we bought a crane "fireball" cam and lifters from a friend who had acquired it before they moved from Hallandale Fl in the 1980s.
Living in Floridaland it gets warm down here, we added another row to the stock radiator. Really does not go over 180 degrees day or night.
Went through the complete front end with all new components ball joints, bushings, new bearings and seals.
Used neoprene energy suspension components on the sway bar links and sway bar bushings.
Tires was a hard decision go with the stock reproductions and join the frufru-squad or go with new age radials a bit wider than stock.
We went with the BF Goodrich tires.
Great grip and ride.
Installed KYB schocks, I think we got the firmest possible.
Dropped the suspension close to two inches.
All these suspension mods made a significant difference in its handling.
As far as brakes we opted to stay stock, rebuilt calipers, rear wheel cylinders, master, did go with all new brake hoses and added stainless steel brake lines all around.
Fuel system stayed with the Holley and stock fuel pump.
Purchased new stainless steel fuel lines and replaced all the gas rubber components.
Ignition stayed stock with the exception of a h.d. brass cap, rotor, addition of a petronix unit and coil.
Exhaust stayed stock exhaust manifolds, but took it to a local muffler shop, had them go back from the h pipe and ran two individual maganaflow mufflers back like the Boss 302 cars, still exits through the shelby rear center port.
You look at the car and it looks stock, the exhaust sounds a bit deeper and handles tight with the old boat anchor 428 up front.
Well that's all we have for now and best of luck on your endeavors
Quote from: shelbymann1970 on November 26, 2025, 07:00:49 PMFirst off if I was looking for what you are I'd buy a Gt350 4 speed. They are cheaper than a 500 and gives you more $$$ for upgrades. Why a 350? well you mentioned handling. Better handling cars to start with. MUCH easier to work on. I own a 68 Gt500, a 69 Mach1 R code and a 70 Gt350 vert. So take you savings and buy a Paxton and a Holley on the 351W and you have your horsepower. Want more? well there are nice aluminum heads to choose from. Add a 5 speed. Lots of suspension upgrades available to choose from. to buy a 500 and modify it for "handling and power" when you will always have a more balanced car with the Gt350 and adding the Paxton could give you the power you need might be a way for you to go. Also with the price difference you might even get yourself a nice crate engine to start with if you want more plug and play and keep the original engine off to the side. Good luck on your endeavor.
Thank you. Psychologically, I need a GT500. I currently own a 2020 GT350, possibly the best Mustang ever built.
Quote from: FL SAAC on November 26, 2025, 07:35:22 PMExcellent question and a very wise decision to enjoy your car
We first went through the engine with a stock rebuild bearings rungs etc. and valve job.
Only change was that we bought a crane "fireball" cam and lifters from a friend who had acquired it before they moved from Hallandale Fl in the 1980s.
Living in Floridaland it gets warm down here, we added another row to the stock radiator. Really does not go over 180 degrees day or night.
Went through the complete front end with all new components ball joints, bushings, new bearings and seals.
Used neoprene energy suspension components on the sway bar links and sway bar bushings.
Tires was a hard decision go with the stock reproductions and join the frufru-squad or go with new age radials a bit wider than stock.
We went with the BF Goodrich tires.
Great grip and ride.
Installed KYB schocks, I think we got the firmest possible.
Dropped the suspension close to two inches.
All these suspension mods made a significant difference in its handling.
As far as brakes we opted to stay stock, rebuilt calipers, rear wheel cylinders, master, did go with all new brake hoses and added stainless steel brake lines all around.
Fuel system stayed with the Holley and stock fuel pump.
Purchased new stainless steel fuel lines and replaced all the gas rubber components.
Ignition stayed stock with the exception of a h.d. brass cap, rotor, addition of a petronix unit and coil.
Exhaust stayed stock exhaust manifolds, but took it to a local muffler shop, had them go back from the h pipe and ran two individual maganaflow mufflers back like the Boss 302 cars, still exits through the shelby rear center port.
You look at the car and it looks stock, the exhaust sounds a bit deeper and handles tight with the old boat anchor 428 up front.
Well that's all we have for now and best of luck on your endeavors
That is a great list! Adding all that to my "Maybe To Do" list. Thanks!
Forgot to mention we had a mellings oil pump installed at the time, new springs on the heads compatible with the crane cam and purchased new Ford stock non-adjustable arms and shafts.
Why stock arms over aftermarket?
Easy peasy
No problems on putting the original valve covers back on and bolt the stock parts down and forget about it.
Now go enjoy the drive !
Wouldn't hurt to consult the Boss 302 chassis modification book. Reprints are available.
I'd add to the advice already given to check if the FE block in the car you are considering has been overbored to .030 or not. If it has, there are lower chances the car's cooling system will cool the engine very well. If I ever bought another big block, I would want a standard bore block, and have 8 sleeves installed instead of boring it.
I'd personally buy a GT350 and buy a stroker crank to make it 408 or 427 CID and 550HP reliable horsepower. There's a guy out in Indiana with a yellow '69 GT350 that built a really nice, tastefully modified car. I don't remember his name, but he would be a good person to contact.
Quote from: Brian350 on November 26, 2025, 08:35:03 PMQuote from: shelbymann1970 on November 26, 2025, 07:00:49 PMFirst off if I was looking for what you are I'd buy a Gt350 4 speed. They are cheaper than a 500 and gives you more $$$ for upgrades. Why a 350? well you mentioned handling. Better handling cars to start with. MUCH easier to work on. I own a 68 Gt500, a 69 Mach1 R code and a 70 Gt350 vert. So take you savings and buy a Paxton and a Holley on the 351W and you have your horsepower. Want more? well there are nice aluminum heads to choose from. Add a 5 speed. Lots of suspension upgrades available to choose from. to buy a 500 and modify it for "handling and power" when you will always have a more balanced car with the Gt350 and adding the Paxton could give you the power you need might be a way for you to go. Also with the price difference you might even get yourself a nice crate engine to start with if you want more plug and play and keep the original engine off to the side. Good luck on your endeavor.
Thank you. Psychologically, I need a GT500. I currently own a 2020 GT350, possibly the best Mustang ever built.
are you planning on working on it yourself? I've owned many 428cars over the years and I've learned the tricks to work on them and they still are a pita. Good luck on your search.
Roller coilsprings perches is a good upgrade from my opinion...
Quote from: FL SAAC on November 27, 2025, 12:15:41 AMForgot to mention we had a mellings oil pump installed at the time, new springs on the heads compatible with the crane cam and purchased new Ford stock non-adjustable arms and shafts.
Why stock arms over aftermarket?
Easy peasy
No problems on putting the original valve covers back on and bolt the stock parts down and forget about it.
Now go enjoy the drive !
Thank you!
Quote from: roddster on November 27, 2025, 12:39:41 PMWouldn't hurt to consult the Boss 302 chassis modification book. Reprints are available.
Thank you, interesting advice...
Quote from: 69 GT350 Vert on November 27, 2025, 01:40:23 PMI'd add to the advice already given to check if the FE block in the car you are considering has been overbored to .030 or not. If it has, there are lower chances the car's cooling system will cool the engine very well. If I ever bought another big block, I would want a standard bore block, and have 8 sleeves installed instead of boring it.
I'd personally buy a GT350 and buy a stroker crank to make it 408 or 427 CID and 550HP reliable horsepower. There's a guy out in Indiana with a yellow '69 GT350 that built a really nice, tastefully modified car. I don't remember his name, but he would be a good person to contact.
Got to be a 500, it's a psychological issue...
[/quote]are you planning on working on it yourself? I've owned many 428cars over the years and I've learned the tricks to work on them and they still are a pita. Good luck on your search.
[/quote]
Not a chance. My skills are washing and waxing...
A GT350 would be a better candidate even if you intend to do a serious lightening of the 428 engine in a GT500.
You can fairly easily increase the CI displacement of the 351 to near that of the stock 428 and in addition lighten that engine with things like aluminum heads.
It all depends on how deep you want to go to re-engineer the car?
Virtually everything is available. 6 speed manual transmissions. 8 speed automatic transmissions. Aluminum 9" rears. Aluminum engine blocks, multiple carb of EFI induction, etc, and they all can be kept to look reasonably stock in most cases.
The 428 performance wise is kind of a dinosaur stock at a max HP level now whereas the 351's are not.
Chassis wise, as suggested, the Off Highway Boss 302 Chassis book is a very good guide as well.
I would recommend though that you do not throw anything away that you take off of the car. Virtually all of these modifications are essentially "day 2" bolt ons and replacing original stock parts now can be difficult, expensive and in some cases virtually impossible.
Quote from: shelbydoug on November 28, 2025, 10:15:20 AMA GT350 would be a better candidate even if you intend to do a serious lightening of the 428 engine in a GT500.
You can fairly easily increase the CI displacement of the 351 to near that of the stock 428 and in addition lighten that engine with things like aluminum heads.
It all depends on how deep you want to go to re-engineer the car?
Virtually everything is available. 6 speed manual transmissions. 8 speed automatic transmissions. Aluminum 9" rears. Aluminum engine blocks, multiple carb of EFI induction, etc, and they all can be kept to look reasonably stock in most cases.
The 428 performance wise is kind of a dinosaur stock at a max HP level now whereas the 351's are not.
Chassis wise, as suggested, the Off Highway Boss 302 Chassis book is a very good guide as well.
I would recommend though that you do not throw anything away that you take off of the car. Virtually all of these modifications are essentially "day 2" bolt ons and replacing original stock parts now can be difficult, expensive and in some cases virtually impossible.
GT500 is my bucket list car. MUST be a 500.
I live in Vegas, and had owned a '70 GT-500 for 27 years. This is nothing different than any vintage car. First, make sure everything is in good working order. Hoses, belts, cables, etc. The FIRST thing I would do is the cooling system/fan/shroud, thermostat, etc. A good/new battery/alt, and especially the positive and ground wires are upgraded. Install a new mini hi torque starter. Fluids are topped off, and replaced. A good suggestion would be to instal an alum intake: weight, and cooling are the goals. Carb, its your choice. However, Holley's are known leakers, I'd personally would swap out for a good Carter/Edelbrock verson. Why? set it and forget it, and dead nuts reliable. Electronic ign is a good upgrade. Trans, power steering and possible engine oil coolers. New upgraded poly/bushings for the sway bars, KYB shocks. Brakes: Baer or Wilwoods are good examples. Be careful not to go way overboard with all of this...costs and labor/time can get expensive.
Quote from: Brian350 on November 28, 2025, 11:32:34 AMQuote from: shelbydoug on November 28, 2025, 10:15:20 AMA GT350 would be a better candidate even if you intend to do a serious lightening of the 428 engine in a GT500.
You can fairly easily increase the CI displacement of the 351 to near that of the stock 428 and in addition lighten that engine with things like aluminum heads.
It all depends on how deep you want to go to re-engineer the car?
Virtually everything is available. 6 speed manual transmissions. 8 speed automatic transmissions. Aluminum 9" rears. Aluminum engine blocks, multiple carb of EFI induction, etc, and they all can be kept to look reasonably stock in most cases.
The 428 performance wise is kind of a dinosaur stock at a max HP level now whereas the 351's are not.
Chassis wise, as suggested, the Off Highway Boss 302 Chassis book is a very good guide as well.
I would recommend though that you do not throw anything away that you take off of the car. Virtually all of these modifications are essentially "day 2" bolt ons and replacing original stock parts now can be difficult, expensive and in some cases virtually impossible.
GT500 is my bucket list car. MUST be a 500.
Big block Mustangs are notoriously difficult to live with in hot climates. I think well deserved.
In the Mustang chassis, the engine just takes up too much of the engine compartment for it to cool well.
Hot restarts often are not possible.
I understand your passion. I have it too. I currently have a 67 GT500, a '68 GT350 and a '73 Pantera. The only one that is close to "stock" is the '67. That one, you don't screw with. You just pray that it starts and runs and then leave it alone. Personally, I can't immagine it (or any of the 3) in Vegas summer heat, but that's just me.
I take exception to the glue on my sneakers melting from the heat of the pavement.
And as a previous poster mentioned, Holley's don't like the heat either.
Best of luck in your endeavor. It will be quite a challenging experiment.
Quote from: shelbydoug on November 28, 2025, 05:00:05 PMQuote from: Brian350 on November 28, 2025, 11:32:34 AMQuote from: shelbydoug on November 28, 2025, 10:15:20 AMA GT350 would be a better candidate even if you intend to do a serious lightening of the 428 engine in a GT500.
You can fairly easily increase the CI displacement of the 351 to near that of the stock 428 and in addition lighten that engine with things like aluminum heads.
It all depends on how deep you want to go to re-engineer the car?
Virtually everything is available. 6 speed manual transmissions. 8 speed automatic transmissions. Aluminum 9" rears. Aluminum engine blocks, multiple carb of EFI induction, etc, and they all can be kept to look reasonably stock in most cases.
The 428 performance wise is kind of a dinosaur stock at a max HP level now whereas the 351's are not.
Chassis wise, as suggested, the Off Highway Boss 302 Chassis book is a very good guide as well.
I would recommend though that you do not throw anything away that you take off of the car. Virtually all of these modifications are essentially "day 2" bolt ons and replacing original stock parts now can be difficult, expensive and in some cases virtually impossible.
GT500 is my bucket list car. MUST be a 500.
Big block Mustangs are notoriously difficult to live with in hot climates. I think well deserved.
In the Mustang chassis, the engine just takes up too much of the engine compartment for it to cool well.
Hot restarts often are not possible.
I understand your passion. I have it too. I currently have a 67 GT500, a '68 GT350 and a '73 Pantera. The only one that is close to "stock" is the '67. That one, you don't screw with. You just pray that it starts and runs and then leave it alone. Personally, I can't immagine it (or any of the 3) in Vegas summer heat, but that's just me.
I take exception to the glue on my sneakers melting from the heat of the pavement.
And as a previous poster mentioned, Holley's don't like the heat either.
Best of luck in your endeavor. It will be quite a challenging experiment.
Thank you. Living in Vegas presents it's own set of challenges.
Quote from: Brian350 on November 25, 2025, 05:43:40 PMLooking at buying a 69/70 GT500. What I want to know is what would be good improvements/upgrades to the car, especially handling, ride and horsepower. I am not looking for a concours level car, so restoration is not my goal. I want the "look" of the 69, but with any improvements that can be made without completely wrecking the car. Things like shocks, stance, coaxing more HP out of the motor. Thoughts? Suggestions?
If you do end up with a GT500
Take a look at "this guys" post when you have an opportunity.
https://www.saac.com/forum/index.php?topic=31570.0
Quote from: FL SAAC on November 29, 2025, 08:38:06 PMQuote from: Brian350 on November 25, 2025, 05:43:40 PMLooking at buying a 69/70 GT500. What I want to know is what would be good improvements/upgrades to the car, especially handling, ride and horsepower. I am not looking for a concours level car, so restoration is not my goal. I want the "look" of the 69, but with any improvements that can be made without completely wrecking the car. Things like shocks, stance, coaxing more HP out of the motor. Thoughts? Suggestions?
If you do end up with a GT500
Take a look at "this guys" post when you have an opportunity.
https://www.saac.com/forum/index.php?topic=31570.0
Thank you!!!
Quote from: Brian350 on November 29, 2025, 02:59:27 PMQuote from: shelbydoug on November 28, 2025, 05:00:05 PMQuote from: Brian350 on November 28, 2025, 11:32:34 AMQuote from: shelbydoug on November 28, 2025, 10:15:20 AMA GT350 would be a better candidate even if you intend to do a serious lightening of the 428 engine in a GT500.
You can fairly easily increase the CI displacement of the 351 to near that of the stock 428 and in addition lighten that engine with things like aluminum heads.
It all depends on how deep you want to go to re-engineer the car?
Virtually everything is available. 6 speed manual transmissions. 8 speed automatic transmissions. Aluminum 9" rears. Aluminum engine blocks, multiple carb of EFI induction, etc, and they all can be kept to look reasonably stock in most cases.
The 428 performance wise is kind of a dinosaur stock at a max HP level now whereas the 351's are not.
Chassis wise, as suggested, the Off Highway Boss 302 Chassis book is a very good guide as well.
I would recommend though that you do not throw anything away that you take off of the car. Virtually all of these modifications are essentially "day 2" bolt ons and replacing original stock parts now can be difficult, expensive and in some cases virtually impossible.
GT500 is my bucket list car. MUST be a 500.
Big block Mustangs are notoriously difficult to live with in hot climates. I think well deserved.
In the Mustang chassis, the engine just takes up too much of the engine compartment for it to cool well.
Hot restarts often are not possible.
I understand your passion. I have it too. I currently have a 67 GT500, a '68 GT350 and a '73 Pantera. The only one that is close to "stock" is the '67. That one, you don't screw with. You just pray that it starts and runs and then leave it alone. Personally, I can't immagine it (or any of the 3) in Vegas summer heat, but that's just me.
I take exception to the glue on my sneakers melting from the heat of the pavement.
And as a previous poster mentioned, Holley's don't like the heat either.
Best of luck in your endeavor. It will be quite a challenging experiment.
Thank you. Living in Vegas presents it's own set of challenges.
I have a feeling that there is no way I could ever know for sure what the "challenges" are unless I live it myself?
I'm guessing on this but I think that you are going to NEED a heavily cooled garage to work on the car? ::)
LOL, got one!
Do you actually have to have A GT500 or just the look of one? Because it would a lot cheaper to recreate the looks of one. And if you don't open the hood, nobody will know, except you of course😄
Roy
Quote from: TA Coupe on December 02, 2025, 10:31:29 PMDo you actually have to have A GT500 or just the look of one? Because it would a lot be a lot cheaper to recreate the looks of one. And if you don't open the hood, nobody will know, except you of course😄
Roy
Not a chance! Real deal or not at all...