Another GT-500 (67) question.

[Mr427]

I asked previously for a set of 428 PI heads for a correct 67-GT500 engine build. Are the C8AE-H heads the correct ones? Seems they are, since they were being cast as early as 1967.

The other two issues regarding what is correct OEm equipment on such an engine:

1. What type of air cleaner did the 1967 GT-500 come with? Pls. note, this car came with the PI intake w. one small vacuum Holley carburetor.

2. Exhaust manifolds: What type of exhaust manifolds were on this engine when installed in the Shelby Mustang?

Thanks and happy motoring to all FEs.

[mrmustang]

According to my records, the C7AX-A heads(casting number C7AE-A) are correct for the 1967 engine in your Shelby, while the heads you have (C8AE-H) were for the thermactor equipped 1968 engines. Surfice to say, your heads are not correct for your car. Exhaust manifolds would be cast iron, C6OE-9430-A(R) AND C7OE-9431-A(L). Finally, the single 4V intakes would have had a 715cfm Holley carb. Any other questions, just let me know.


Bill S.
SAAC member since 1981
MCA member since 1981

[Mr427]

Bill: I have been researching this issue. The heads need to be the C7AE variety. You gave me casting numbers on the manifolds. What would these look like? Are they cast ireon headers, logs or the in between dual bolt pattern as was common on many 66-70 FE´s?

Finally, what type of air cleaner was installed on the single 4V Holley equipped 1967 Gt-500?

[Keith Lyles]

If my memory serves me correct, the 67 GT-500 had dual carbs. Something like 650's I think. Anyway I can check my literature and get back to you. Most of the dual carb units were changed to singles by owners because there were real tough to keep tuned. Mr. Mustang, jump in if I am wrong. If you are looking to go OEM all the way, better look to pay $2500-$3000 for the right carb set-up with air cleaner.

Keith

[Mr427]

Surprises all the way on this intake issue. I thought it was the other way around. Shelby American produced the cars with single four barrels, but the 2x4 option was a very popular over-the-counter item, which many owners installed on a variety of Fords during the mid-to late sixties on their FE´s. But this may be a fluke. I just know that this particular car had a 428PI intake with either a C6AE or C7AE casting nr. when it came into this area in 1972. So, what WAS the factory setup on these cars as they rolled out of the hangar? Shelby may have done it one way, but Ford did it another way. Only the first 100 GT-500´s in the ´67 run were acutally BUILT in LA. Ford took over the assembly of the Shelby items long before the mid-point, because of semantic problems and other between Mr. Shelby himelf and Ford´s staff, according to Wallace Wyss´s book "Shelby Wildlife".

Now as for the exhaust manifolds, what type were they? Were they the same as on a GT-390 in a Farilane- Cyclone, with dual bolt patterns or were they the log type??

[GEORGE ANDERSON]

These are some recent restoration images from a 67 GT500 that may be of some interest to you...
George

Heads

Intake

Exhaust Manifolds

Other completion images

[Joe Rutledge]

George's pics show exactly what was there. The 67 big block cars came with a factory 2 * 4 induction system with a black "cobra" air cleaner. The carbs were 600 cfm holleys (made for the 2 * 4 application) and were mounted backwards. As Georges pics show, the engine also had crappy exhaust manifolds very similar/or same to the 67 390 GT Mustangs. Kind of an exhaust tournequet - in fact the exhaust system was probably responsibile for the so so performance numbers in the rags at the time. The first thing we did back then was can the manifolds and put on headers. In 1972 my stock 500 could turn a high 13 @ 105, but that was with the transverse muffler excised (with stock manifolds). Later, it was popular to try to add the 428 CJ exhaust manifolds, as they were better. There was a subtle difference between the 67 & 68 valve covers. I am sure that SAAC has the specifics, but I am not aware of any "normal" 67 500 having a single four out of the factory.

Still have the car today, engine is exactly as George's pics indicate.

Joe

[Joe Rutledge]

Just a minor point on the book. Wally wrote one of the first books on the Shelby cars in the early 70's. His background was more on the journalist side than automotive. No disrespect intended, he worked very hard on the book, but there are some inaccuracy's in it. I remember that while he was writing it, he interviewed a lot of people from the early SAAC club (such as Rick Kopec) and was pointed to "expert" individuals for the various years. "Expert" individuals did not necessarily mean factory people, they could also just be knowledgable enthusiasts. One of them being my brother for some of the input on the GT500 cars. The conversations were over the phone so it would be easy to make mistakes. Also, early on in the club there was a real focus on the early Shelby cars (especially small block Cobras and 65 GT-350's). I remember Rick's point to my brother was to try to make sure discussions were accurate, as once it is "written" it becomes "fact". So I would use the book as an information source, but not necessarily a bible.

[tonysshelbys]

no, no, no! Ford did not take over production of Shelby GT-350's and 500's until the 1968 model year when they assumed responsibility for the product for two reasons: 1) Shelby American had lost the lease for the 6501 West Imperial ("Airport") location and 2) Ford felt the quality of the finished fiberglass was not up to their standards and they wanted control so A.O. Smith in Ionia, Michigan began production of Shelbys beginning with the 1968 model year. See the 1997 Shelby World Registry. Wally Wyss is a nice guy but Kopec has said many times that Shelby's Wildlife had many errors in the first edition and he had to correct some of those errors for the later edition.

[Mr427]

Thanks guys. I really appreciate the feedback. I have been in touch with Dave Matthews of SAAC, he is the registrar for the club and he has given me the exact same points as you have. So, they ALL came w. dual Holleys, which explains the comment to that effect that I read in an English automagazine from the period. They were testing the GT-500 and floored the trottle and then they said: "At firt the big V-8 gasps, then the car hunches forward with a loud bellow".

I thought that was hilarious, but the European motoring press made mockery of any claims these cars madu to being sports cars.

Still, I wonder about the exhaust manifolds and the C7AE heads. Dave says they did not have the dual bolt pattern on the GT-500. That leaves me with an anomaly: The pictures of the engine above clearly show a semi horizontal or slanted bolt pattern, instead of the typical vertical FE pattern. Did the C7AE heads, really have the dual pattern?

I am clear on all the issues now, except this one. Thanks again and all the best.

[Joe Rutledge]

My memory could be faded, but I remember the heads being the same as in George's photos (having both the verticle and horizontal bolt holes). So when you put on headers you could use either or all bolt holes. The exhaust manifolds look to be the correct ones (mine are all rusty). The passenger side exhaust manifold has a positively tiny diameter where the heat riser flipper is (when you consider it is behind a big block). The only minor diff I noticed is that our fuel pumps had the canister type of fuel filter as compared to the later style without filter on it. Don't know if all 67's came one way, or whether the fuel pump pictured is from a 68. There were minor diff's on oil filler caps and things like that from the factory.

If it really makes a diff I could check tonight in the garage, as I believe the original heads are out there somewhere. The exhaust manifolds are also. If you are going for absolutely original, then you have no choice but to use the original (terrible) exhaust manifolds. If you are allowed to cheat a little, you can use the later 428CJ exhaust manifolds, which have to be worth at least 10 - 15 hp, and look nearly the same. It would require different H-pipes, etc. I do recall seeing them installed on a 67 mustang in years gone by, but I never did it myself, so I can not say for sure there would / would not be some minor issues which had to be overcome.

As to the comment that dual quads were hard to tune, I never really found that to be really true (assuming that they were the original type which were designed for the task). The factory jetting was fine (for NJ), maybe a tad rich on the primaries. The key was to end up with all the idle screws nearly the same after you were done fooling around.

Joe

[Mr427]

Joe and others, thanks again. I have this picture just about made. Recieved positive ID from Dave last night. The C7AE heads obviously have the dual pattern. I can now proceed to assemble and buy whatever else is still missing.

I still have two issues regarding the engine in this car. How does it drive? How is the idle with the stock camshaft?

I bought the book by Wyss very early on, because I had the car at the time. IT missed out on one major point regarding that particular car. It had been used by Ford, probably in 1966 as a promotional vehicle, then with a Paxton blower or two. Does anyone know anything more about that issue. This was confirmed by several sources. VIN 67412F5U00433

I came across this informaion in a magazine in an articel by Jim Hilson, Car Life, I think it was. I wrote to Jim and asked him about it and he confirmed that this was the same car.

[Joe Rutledge]

I looked at the original engine last night, and I was not quite right. The two outer exhaust ports have the 4-bolt setup, the two inner ones have a 3-bolt setup, with the bottom bolt hole not being drilled. I am pretty sure about the ones on my engine, I do not think it is grime which is obscuring the bottom bolt holes.
I think the casting number was C7AE-A.

The original 428 / dual quad had very good street manners. It had the same hydraulic cam as a 390GT. It idled very well, pulled well low down. I remember I used to shift between 5400 & 5500 with the original 350 open rear. If your car had a non-productuion 428 PI (police interceptor) it may or may not have had the 390GT cam. There were some PI's in that era that had a solid cam. As long as the dual quads vacuum secondaries opened up properly, there was quite a rush when they kicked in. Initially flooring it gave you the rough equivalent of a 600cfm double pumper (two accelerator pumps) until the vacuum secs kicked in. Very very drivable - only a few situations where a single four was more responsive at lower RPM. I always felt that my car was about equal to my brothers friend's 69 CJ Mustang (after I removed the transverse muffler). The CJ was probably a little more powerful, but I think the 67 was a little lighter. At the dragstrip mine MPH'd a little more, my brothers was a little slower (105+ to 104+). The CJ squealed tires more when flooring it (advantage of single four).

I am pretty sure the exhaust manifolds were the same as a 390GT Mustang, there should be someone else who can confirm this. They made pretty good boat anchors for lake boats.

I do not really know anything about special or promotional vehicles of that era.

[RedCSX1]

These parts are easy to locate. THe 67 GT-500 came with Ford GT Heads and Manifolds. East stuff to find. You should also be able to find the dueal carb intake or you can use a Blue Thunder which is very similar. The BJ and BK carbs are reproduced by Holley. See my gallery for pictures of my old 67 GT-500.

Morgan