I've been researching the difference between the 1968 J Code 302 4V engine and the GT350 Shelby engine. Compiling casting numbers, etc. Based on my research and feedback / website links (like MustangTek and Coral Snake sites) from some of my SAAC friends, it appears the only difference is the intake. J Code has the C8ZE iron casting while the GT350 has the S7MS aluminum. Can anyone else confirm or refute this? The one item that I really can't seem to find is information on the camshaft (for either engine). Original part number, lift, duration, etc. Can anyone shed some light on this for me?
Thanks, Greg P.
Internals are identical. It is the same engine with cosmetic changes only. The secret was actually a higher rear end ratio, than most 1968 J codes.
At start of year, cast iron intakes and Autolite carbs were used on GT350s. In fact most GT350s received the iron intakes.
A few very late cars and cars returned for a recall received aluminum intakes and S8 carburetors.
Other than that, the valve covers and air cleaners are the only other varaiations.
On my 68 350's one had a S2MS and the other had the S7MS, I always thought they used what was on hand for the recall
There was actually a recall kit. The S2 manifold is accepted, but technically not correct. if you had that I would argue you should use the Autolite carb
+1 on the information supplied by Coralsnake. Pete has spent years gathering information on '68's . One of my friends who bought a '68 350 got the recall notice but only got the intake manifold , not the carb as it was backordered. He traded the '68 in on a '69 GT500 before the carb came in. So one '68 blue 4spd 350 had the big number S2MS intake with the Autolite carb.
Randy
Just in case the old Road and Track article comes around
http://www.thecoralsnake.com/Curiousity
When did they end the use of the Try Y Headers and the Aluminum T Oil Pan?
They were not used on 1968s
Quote from: tesgt350 on November 28, 2018, 01:32:09 PM
When did they end the use of the Try Y Headers and the Aluminum T Oil Pan?
The '66 GT350 was the last to use them.
Quote from: Coralsnake on November 28, 2018, 11:34:54 AM
There was actually a recall kit. The S2 manifold is accepted, but technically not correct. if you had that I would argue you should use the Autolite carb
I agree with the above statement that the large number S2MS intake is not technically correct because it did not come with the official kit . I know Pete has seen a lot of the large letter S2MS intake . I do think it is just as historically correct under most circumstances. I have for example found more of the large number S2MS intake on unmolested 68 GT350's then the S7MS marked ones . The large number intake must have been at the least a very available intake for dealers to complete the recall. Although not the official I suspect it was a on the shelf or more available alternative if they didn't want to wait because of maybe a supply issue for the S7MS that came in the official recall kit.
My personal observations are that the "initial" recall kits were more complete and did use the S7MS intake. At "some point" , which I was never able to track down, the large number S2MS manifold was in the kit and the kit became two separate boxes instead of one . That "to me" is why my friend never got his carburetor , but it "could" also have been the dealer stealing his carburetor in reality.
Randy
Great feedback. So to be clear:
Coral Snake: Are you saying that the C8ZE intake was also used on the GT350 prior to the recall? So that would be correct or depending on the recall kit it could also be the S7MS or the S2MS?
All. What is the correct cam part number for the '68 J Code?
If you are looking to make your car the way they were, it used stock 302 engine components. 2v-4v used same cams no performance cams came originally with those engines. Any auto parts or engine shop can get you a stock cam. Good Luck!
Quote
Coral Snake: Are you saying that the C8ZE intake was also used on the GT350 prior to the recall? So that would be correct or depending on the recall kit it could also be the S7MS or the S2MS?
Yes, the cast iron C8ZE is correct for the GT350s prior to recall.
Yes, it would be correct. If you are going to say the car was recalled, a S7MS is a better choice, but a S2MS will be oksy.
http://www.thecoralsnake.com/GT350a (http://www.thecoralsnake.com/GT350a)
http://www.thecoralsnake.com/GT350b (http://www.thecoralsnake.com/GT350b)
http://www.thecoralsnake.com/intakes.HTML (http://www.thecoralsnake.com/intakes.HTML)
Your research is already done.🤡
Thanks again everyone. Great information and very helpful. I think I have the numbers under control now. BTW, what was the recall done for? Were there defective C8ZE intakes or was it for a performance upgrade?
They had intended to use the aluminum intake all along, but could not get it certified until late in the 1968 model year.
That intake and the Holley S8MS carb change the nature of that engine quite a bit. Considering the release date and the last build dates of the 68 GT350's, there could not have been many installed in original production.
The 350's were almost done by that date and it was KR territory from there in.
Spot on!
I once asked about the cam and headers on that engine. I can't remember who it was. One of the Ford people. He shrugged his shoulders and said that "they EXPECTED" buyers to do a cam and headers on it.
I think really what happened though is the '68 GT350 got caught between a last minute cancellation of the 302 Tunnel port and the switching over to the Boss 302 which was still not completed enough for production? So the 302 J was the next best alternative.
The late decision on the Holley and Cobra intake fits into that entire scenario? Three to four months on a change like that is tomorrow for Ford. I don't think that there are ANY S8MS Holley's that have an earlier then May 1 production date but the things are so rare it's next to impossible to survey that.
Are there any November '68 Shelby's? I haven't looked lately. I thought December just before Christmas was around the first production? Phil's car is pretty early with the early lower nose. Is that early block on your website his? That doens't fit into the two week sweet spot for the engine vs. car build date?
Neither of the S8MS carbs are cheapo's at all.
Quote from: shelbydoug on November 29, 2018, 10:58:58 AM
I once asked about the cam and headers on that engine. I can't remember who it was. One of the Ford people. He shrugged his shoulders and said that "they EXPECTED" buyers to do a cam and headers on it.
I think really what happened though is the '68 GT350 got caught between a last minute cancellation of the 302 Tunnel port and the switching over to the Boss 302 which was still not completed enough for production? So the 302 J was the next best alternative.
The late decision on the Holley and Cobra intake fits into that entire scenario? Three to four months on a change like that is tomorrow for Ford. I don't think that there are ANY S8MS Holley's that have an earlier then May 1 production date but the things are so rare it's next to impossible to survey that.
Are there any November '68 Shelby's? I haven't looked lately. I thought December just before Christmas was around the first production? Phil's car is pretty early with the early lower nose. Is that early block on your website his? That doens't fit into the two week sweet spot for the engine vs. car build date?
Neither of the S8MS carbs are cheapo's at all.
Here is a S8MS-C with a 831 date (first week of March 1968) that I have on my shelf.
Have you seen an earlier date?
I can't say that I have but I have not been paying enough attention to that detail ether. I only thought to look when you brought it up.
Mine had the same date code. I wonder if they are batch coded? Don't Holley's tend to be? Still, they wouldn't have been installed until the intakes were ready AND would they have been installed by Ford at the engine assembly plant?
Someone needs to do a survey? Someone highly qualified and motivated? Hey Pete? ;D
Doug ,
At that time , Holley could easily build 100 carburetors in a day and the carbs were coded by the week so 500 or more could have the same date. The Ford purchase order quantity would be the determining factor. IMHO anyway.
Randy
Quote from: gt350hr on November 30, 2018, 11:31:42 AM
Doug ,
At that time , Holley could easily build 100 carburetors in a day and the carbs were coded by the week so 500 or more could have the same date. The Ford purchase order quantity would be the determining factor. IMHO anyway.
Randy
Correct. The question is, how many were ordered and when. GT350 production was almost over by the time the intake became available for production and even so, look at the total production of '68 GT350's, divided by two for automatics and manuals, then whatever was thought needed for service.
I have seen several with 933 or 934 production dates. Those obviously are service, over the counter carbs.
The other thing is even if Holley had 500 a day production capability, how long is tomorrow? I doubt if you ordered them Monday morning, they were done by Monday afternoon?
Then there is the question of the dealers not installing the Holleys, just the intakes on the recalls, etc, etc.
Looking at both carbs, I'm not sure why there needed to be an automatic version and a manual trans version. The linkage is the same as far as I see it. I don't see a kick down lever on the auto version BUT I only have had the manual version.
These were both 1860's too and not the cheaper 1850's with secondary metering plates. They had all the bells and whistles for the time. Not a cheap carb new.
The rarity of the '68 carbs is on par with the '65 GT350 carbs. Few '68s have them installed so it's difficult to do a study with any significance.
It's entirely possible that the original production carbs are all dated 833 like the one that Bob posted.
Idle calibration differences between stick and auto. Harold Droste was the Holley/ Ford-Autolite carb specialist and "made them right" for each need.
Randy
831, 833, 841 are dates that are feasible for assembly line (Smith) install. There weren't a lot of factory installs but the ones I've seen, maybe 5 cars, have all had the S7 . Majority of dealer installs are the latest S2 with the coil pedestal
Doug ,
Small block kick down was on the gas pedal , not the carburetor , so the linkage was the same regardless. As an FYI there was also "going to be" a 302 Hi po even before the tunnel port fiasco, but Ford couldn't get smog approval on it either. Ford desperately needed a small block performance engine but '68 was also hurt by the strike in late '67 ( '68 model year) as well as the smog compliance issue. Stepping back from 306 to 230 hp was not a great selling point!
Randy
Randy, have you ever heard of the plan to offer overbored cobra jets?
Pete,
The "X" garage built "more than one" 447-448 ci engine. One was used in a '67 Mustang coupe to beat Tasca's KR8 at thr Dearborn test track ( Oh not too much press on that one HUH? The 428 ( 4.130 bore) block was not meant to be bored much bigger so the 427 block had to be used with the 428 (3.980 stroke) crank. The engine was too expensive for the "bean counters" and too dirty for the "sniffers" at the emissions lab. Both equaled doom.
Is that the one you are referring to?
Randy
Car #006 was built on Nov 14, 1967 and had the cast iron intake with Autolite 4300 carb.
This car has a complete and unbroken document history and belongs to the original owner Mike Shally