Collaborative early a experiment

KosmicKuda said
Just my 2 cents. I don't have a V-8 narrow body.

If you are going to modify stock style exhaust manifolds to fit, 1/32"-1/16" clearance is just too tight. It may work for one particular car but if the same manifold is tried on a different car, you may have 1/4" clearance or 1/4" interference. In my opinion, you need to "kill" the problem and err on the safe side.

Angle milling a mounting face may help, I don't know, but depending on how extreme the angle needs to be, you may want to spot face the bolt head area so it parallels the face.

But the info you are gathering is a great thing to have and share.

I agree KKuda, every car will be a little different (clearance wise). There are numerous ways to attack this issue. I could get someone with a early A (with no engine installed) to measure the two closest points inner fender to inner fender. Hopefully I could get numerous members to do this, at least all the members with their engines out!! This way we could get a good idea of the variation between cars. I have a 318 sitting in my garage. I could throw the heads on it and the exhaust manifolds and measure the width (outside to outside) on the exhaust manifolds. Also, and I'm not sure if this is doable, someone with an Early A could spread their inner fenders using a porta power or bottle jack to get just another 1/4" of width. But again, I'm not sure what other problems it might cause. If I cut the manifold mating surface at an angle I would have to also cut (spot face) the bolt head surface or you might "snap off" a bolt head forcing it to push too hard against a surface that is not parallel to the underside of the bolt head. Cutting the mating surface and spot facing the bolt head area would basically double the machining costs and I would lose any potential future buyers. I have to keep costs down or we're back to the cost of expensive headers.

And you are correct, the manifolds do need to be machined in such a way that they fit most of the Early As out there. Also, the criteria I listed at the beginning of this thread calls for someone who isn't afraid to do a little creative engineering to get them to fit. I know it's been done before but there just isn't enough documentation to make Early A owners feel comfortable about buying the late 60s 340 driver paired with the 360 magnum passenger. I already know that the price I sell these manifolds for is reasonable because I can't keep enough in stock. So my prices are OK, I have to do my best to keep the price down!!
Thanks for your great ideas!!!!
Treblig