Does anyone know if in fact the C6AE-J or R heads were installed on the 1967 shelby non (cobra jet 428)using the gt 390 exhaust manifold,i was looking on the shelby websight that shows this head as a 428 PI.Also the NHRA blueprint spec shows this head as a shelby 428 shelby head.THANKS
The C6AE-R heads certainly could have been used on a '67 Shelby GT500. Like any other 428 in 1967 the heads are nothing special. The same heads were used on 352 pickup trucks for example.
If these heads were used in a unit body car (Mustang / Cougar, Fairlane Comet Shelby etc) then they were drilled for 14 bolt pattern to be able to use the unit body exhaust manifolds. They are common and cheap to buy. Core sets with 8 bolt holes typically sell for $100 - $200 a pair. You can drill the 8 bolt heads to fit the 14 bolt pattern if desired.
has big / MR type ports and was used on a bunch of different applications, should be easy to find. Add CJ size valves, clean up the bowls and massage the exhaust and they can flow some pretty impressive numbers. Here's a post on them and a few others: http://www.network54.com/Forum/74182/message/986317828/
Like you said, the C3 and C2 heads would be better if you're looking for higher compression. But I think the flow numbers would be pretty much the same. Also, I think the C4AE-G heads are going to be cheaper and easier to find.
Don`t forget that all the pre 66 heads are lacking the material to drill and tap for the diagonal exhaust manifold bolt pattern, which you will need if the heads are to be used with exhaust manifolds in a shock tower equipped vehicle.
428 powered Fairmont drag car, Best ET:email@example.comMPH, best 60 ft: 1.32
59 Meteor 2 dr. sedan 332, Ford O Matic
74 F350 ramp truck 390 4speed
I have heard it is possible but every original GT500 I have ever seen...
January 20 2008, 10:06 AM
Every original GT500 I have ever seen had C7AE-A heads and I know the first 67's all had these so I can't imagine Ford dragging out old tooling to make more of last years parts when the new parts were readily available. I have heard a lot of people say that various 67's did have teh C6AE-R heads but I have yet to find an original verifiable car that did and I have been looking for more than a couple of decades. Hawkrod
FE head is the one you have available when you need it !!!! It is pretty well evidenced here that all will flow the air you need at SOME time during youre rpm range.. In reality, due to their large casted size, what they do BEST is...keep the piston IN the hole when the rod breaks !!!
It only takes about 250 cfm at .500 to run 10's with a 3400 pound Stocker, Edelbrocks for Stock flow a little more, but they are also 170cc. The 140cc head that is a little bit down on flow to the Ed head will run faster because of volume........cipher on that a little. "R" heads are good. So are C4-G's. I suspect the short port truck heads might be better than both on the street. If it was legal, the first thing I'd do to the 390 Stockers is raise the floor, which is done already on the later truck heads. Street engines need velocity. If you are not 450+ cubes and 6500+ rpm, use a small port with some tweaking. It is the same reason the Streetmaster manifold works so well in streetable applications.