quest for a 427 for my 68 GT-E

What I have now is a fully rebuilt 427 from a 63 Galaxie, with dual 4’s. The Block’s casting is C5AE-A, heads are C3AE-6090-D and the intake is C3AE-9425-J. Sort of a Frankenstein-427.
My Dad bought the engine 20+years ago thinking someday he would put it in the GT-E to replace the 429 He and I shoe-horned into it in 1979 (replacing the 351W placed in it to compensate for the 427 & C6 having been stolen out of it). My Dad’s thinking was “well it had a 427 in it, and this is a 427”. But, as I’m finding out, a 427 from a Full-sized Galaxy doesn’t fit unmodified into a 68 GT-E.

So, I’m interested in any ideas on 1) how to modify this 427 to work (correct heads, intake & exhaust manifold) so that it will fit and be as correct as possible or 2) where one might find a buildable correct engine w/o selling a child, or two.

any leads would be greatly appreciated.

Happy to provide additional details and contact info privately.

Joe Manek.

Here is the hardest portion of the engine to find

If It were mine, I would have the heads redrilled for a set of reproduction Cobra Jet exhaust manifolds. That should solve the fit issue on the exhaust side, and breathe better than the 390 GT manifolds that came on the W code 427. The intake you have is a low riser and I think it might fit under the hood, maybe Royce will chime in as he has more knowledge of that part than I do.

That engine would work fine with a set of headers. Installing some of the header bolts will be a “special” kind of job…

A proper GT-E block is danged hard to find too, perhaps harder to find than a set of heads. Don is asking a pretty reasonable number for the heads, I am going to be surprised if he owns them much longer than the end of the month.

If your not looking for numbers matching, the block you have is just fine, the heads are low riser, as is the intake, that’s not your problem. It’s the exhaust, as other have suggested, there are 2 ways to fix that problem, easiest is to get a set of headers.

Actually the block is a slight problem too. The 1963 block only has two motor mount bolt holes, versus four on 1965 and later blocks. So the GT-E motor mounts won’t bolt up except to one of the bolts on each side.

It’s not a big problem. The motor mount block plates can be drilled to work with the early block.

He says the block casting is C5AE-A that’s not a 63 two holer, as you said yourself, he needs a 4 holer, a C5AE-A, which he has.

If i buy Don’s heads how difficult will it be to get a set of 14 hole exhaust manifolds that work. Better to get a correct single 4 intake/carb. Would the intake and carbs i have work with my block and Don’s heads? Sorry to ask dumb question, but 427 build mistakes are a bit expensive.



Don’s heads are low riser, so yes they would work with the intake you have and the block.

i have C1AE Heads in my GT-E Clone with 8 Hole bolt pattern. I use FPA Tri-Y Headers especially build for me to fit the old heads in the cougar…it worked perfect.

Exhaust manifolds for the GT-E 427 are cheap and easy to find because they are the same as 390GT or 390-2V X code in Mustang / Cougar / Comet / Fairlane from 1967 - 69. You can find them for $200 - $300 on eBay.

Well, i bought Don’s heads. Supposed to arrive today, if UPS tracking is to be trusted. Excited about having an engine/head/exhaust manifold combo that will fit in the car. :slight_smile:

Wow, those are some expensive pieces! Curious what made you decide to go that route rather than the available special application headers or drilling for the available and better flowing CJ manifolds?

Nice! J code heads going back in a gte. If he wants, two holes drilled and he can run the cj exhausts.

I am curious as to how the GT manifold ports match up with the J head exhaust ports, especially at the top. Mine did not match well so I went with CJ manifolds.

Joe, What is the build date of your GTE?

it’s taken some time, but now to the point where I’m trying to mate up the exhaust manifolds to the J head I purchased from Don. I believe I have the correct manifolds (C760E-9432-A and C60E-9430-A), but…the ports don’t mate up very well, almost no coverage on the top of the Ports. I’d say it’s about 1/8" overlay. I’m guessing assured to leak. I read an old post on ( where this same topic was discussed. anyone else seen this? suggestions? In the Post Jim P. indicated that 428 manifolds would work as long as head were drilled for 14 holes, but all of the 428 428CJ manifolds I’ve seen on the web are 8 bolt diagonal with the exception of the rear driver’s side port, which is vertical.
I suspect I’m missing something and am certainly confused. any insight from you wise cat-wranglers, as always, would be much appreciated.


typo- C70E-9431-A. fingers in their home positions before typing…

I’m dealing with the same issue except I’m putting them on the C8OE-N Heads and the fit is terrible!. Only 1/8 inch of the upper flange on the exhaust manifold seals to the head above the ports. This is the case on 7 cylinders and it is less on the number 3 port. That means that 1/4 inch of that upper flange is covering the port and thus restricting flow. If I remember correctly the front and back ports also mismatch on a side. Then add in the fact that my surfaces on the manifolds are not perfect and I figured no chance of a good seal.

I bought the SCE Copper gaskets and shaped them to fit the manifold and used them. I’m pretty happy with the fit but you must force the manifold up after the bolts are in and get as much coverage as possible. I have not reinstalled the engine since I am waiting for drivers exhaust manifold to come in the mail. I found my original to have been repaired and it is starting to crack in the weld area.

I have a lot of pictures of how I combated this issue and will post them when I get home. I have not downloaded them from the camera yet since I worked on that issue this weekend.

I took these the other day, that is pretty typical of the fit. Not real great pictures but you can see the mismatch at the top.