Recently bought a 69 GT500. Tons of problems, knocking them down one by one. ($$$$$) Looks like I either need my fuel pump rebuilt or replaced. Maybe a vapor lock issue. So, question. Better to rebuild the fuel pump? Replace it, but with what? Or do the dirty deed and go with EFI? Thoughts? Advice?
Overheating problems. Already have a clutch fan. Radiator looks pretty rusty inside. Repair or replace? Replace with what?
Thanks in advance for all the input, it's greatly appreciated!
Quote from: Brian350 on May 07, 2026, 12:42:24 AMRecently bought a 69 GT500. Tons of problems, knocking them down one by one. ($$$$$) Looks like I either need my fuel pump rebuilt or replaced. Maybe a vapor lock issue. So, question. Better to rebuild the fuel pump? Replace it, but with what? Or do the dirty deed and go with EFI? Thoughts? Advice?
Overheating problems. Already have a clutch fan. Radiator looks pretty rusty inside. Repair or replace? Replace with what?
Thanks in advance for all the input, it's greatly appreciated!
The short answer is to rebuild components if they are original assemblyline type. Mods like efi on these cars typically are frowned at and diminish the value of the car by the amount in labor and materials to return it to stock.
"If" the radiator looks rusty inside, you can bet so are the water jackets. Rust is an insulator.
Look up cooling system cleaning on the internet.
Quote from: Bob Gaines on May 07, 2026, 11:25:12 AMQuote from: Brian350 on May 07, 2026, 12:42:24 AMRecently bought a 69 GT500. Tons of problems, knocking them down one by one. ($$$$$) Looks like I either need my fuel pump rebuilt or replaced. Maybe a vapor lock issue. So, question. Better to rebuild the fuel pump? Replace it, but with what? Or do the dirty deed and go with EFI? Thoughts? Advice?
Overheating problems. Already have a clutch fan. Radiator looks pretty rusty inside. Repair or replace? Replace with what?
Thanks in advance for all the input, it's greatly appreciated!
The short answer is to rebuild components if they are original assemblyline type. Mods like efi on these cars typically are frowned at and diminish the value of the car by the amount in labor and materials to return it to stock.
Understood...
Quote from: roddster on May 07, 2026, 12:12:59 PM"If" the radiator looks rusty inside, you can bet so are the water jackets. Rust is an insulator.
Look up cooling system cleaning on the internet.
Roger that...
Ok, so the shop is going to rebuild the fuel pump and add a vapor return line. They're going to pull the radiator for either rebuild or replacement as well as the water pump and thermostat. We'll see how all that goe$$$$$$$$$...
Quote from: Brian350 on May 08, 2026, 04:43:53 PMOk, so the shop is going to rebuild the fuel pump and add a vapor return line. They're going to pull the radiator for either rebuild or replacement as well as the water pump and thermostat. We'll see how all that goe$$$$$$$$$...
Could you elaborate on the purpose of the vapor return line and where you are adding it? You had best do your research so that you can determine if the radiator is original or not. An original 69 GT500 radiator is a valuable and rare part. The top tank ,the side straps and the bottom tank are all valuable components in their own right. Typical shops replace radiators with generic replacements instead of rebuilding because it takes too much time and trouble. A generic radiator can be easily identified by a knowledgeable enthusiast.
I wouldn't go with EFI. I had a Sniper EFI on my '69 GT350. It was great for 4 years, but then it had an internal fuel driver failure. It dumped a lot of fuel into my intake and cylinders because of a false lean condition. These EFI systems do not have any programming or prevention built in if a failure occurs like OEM systems do on newer cars. When they fail, they can create a false lean or false rich condition that can damage your engine.
A good explanation of how efi does not work so well as a conversion.
Quote from: Bob Gaines on May 08, 2026, 08:50:40 PMQuote from: Brian350 on May 08, 2026, 04:43:53 PMOk, so the shop is going to rebuild the fuel pump and add a vapor return line. They're going to pull the radiator for either rebuild or replacement as well as the water pump and thermostat. We'll see how all that goe$$$$$$$$$...
Could you elaborate on the purpose of the vapor return line and where you are adding it? You had best do your research so that you can determine if the radiator is original or not. An original 69 GT500 radiator is a valuable and rare part. The top tank ,the side straps and the bottom tank are all valuable components in their own right. Typical shops replace radiators with generic replacements instead of rebuilding because it takes too much time and trouble. A generic radiator can be easily identified by a knowledgeable enthusiast.
I'll let you know about the vapor line, undecided so far but talked about running it back to the gas tanks. The radiator has been discussed as you suggest, unsure about exactly what it needs, should find out this coming week. Thank you...
Quote from: 69 GT350 Vert on May 09, 2026, 08:36:22 AMI wouldn't go with EFI. I had a Sniper EFI on my '69 GT350. It was great for 4 years, but then it had an internal fuel driver failure. It dumped a lot of fuel into my intake and cylinders because of a false lean condition. These EFI systems do not have any programming or prevention built in if a failure occurs like OEM systems do on newer cars. When they fail, they can create a false lean or false rich condition that can damage your engine.
I keep hearing opinions both ways on this topic, staying with the carb for now...