The Stovebolt Site Forums The Shop Area Engine Shop Bolt pattern on heads

I have been searching over and over for a exhaust manifold for my 350 SBC in my 49 truck. Due to the tight compartment and steering arms I was limited.
I thought i found the perfect match manifold. It came off a 1976 truck and it exhaust to the back. Well the bolt pattern on the the manifold is a 1/4 different than the heads. The heads from the two farthest bolt holes it's 17 1/2 center to center and the manifolds is 17 1/4. The problem is I do not know what year SBC i have or the type of heads. I looked all over for the casting no. on the block. They say it should be on the passenger side or it might be on the bell housing either I looked and still did not find it. I cant't see the bell housing area due to the tranny. My question how do i go about looking for a manifold if I don't know what year engine i have. I tried to find the bolt patterns on different heads but had no luck. I'm guessing the engin is s a mid 70's

mark

Hy 49dream, Chevy exhaust manifolds which have their "log" below the exhaust ports, tend to "shrink" or curl in on the ends when they are removed. Because of this problem, a lot of the later ones were cast with a connecter bar across the top. There are turnbuckle type pushing tools available, to stretch the manifold back into shape, I would heat it up ib the oven before I tried to stretch it a 1/4" though. I dont remove those manifolds anymore without having those tools in place to hold the manifold, so it can't shrink, hope that helps