350 exhaust manifolds

jhodgson

New member
I am building a Buick Skylark 350 for street/parking lot use. I do not want to use long tube headers and can't find anyone who makes shortys. The original manifolds on my 1968 engine accept 2" down pipes. Do any of the later manifolds or those for a GS accept larger or am I going to be stuck with modifying a set of Chevy 350 shortys for a Chevelle? Unfortunately the exhaust manifold casting number reference doesn't list the down pipe sizes.
 
I think you are stuck with full length headers or the original factory manifolds. The early factory manifolds all exit in the same size, but it has been reported the 73 and later manifolds with 350-4s in the full size cars exit the manifold at 2.5". I can't say for sure, but it is a place to start.


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jhodgson

New member
Thanks

Thanks for the manifold feedback. Looks like I'm going to get to spend some quality time poking around the local wrecking yards.
I think you are stuck with full length headers or the original factory manifolds. The early factory manifolds all exit in the same size, but it has been reported the 73 and later manifolds with 350-4s in the full size cars exit the manifold at 2.5". I can't say for sure, but it is a place to start.


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jhodgson

New member
Unicorn?

Thanks for the manifold feedback. Looks like I'm going to get to spend some quality time poking around the local wrecking yards.
I am beginning to think that Buick 350 exhaust manifolds with down pipes bigger than 2" are about as rare as Unicorns. There was a guy in Cleveland parting out a 78 LeSabre who said it had 2-1/2" down pipes but he sold the car before I could actually see it. I've looked at half a dozen full size mid 70's 350's and none have been any bigger than 2".

If they exist, does anyboady out there have a set they would sell?

Thanks
 
Exhaust manifold mod

I have 2 sets of 350 exhaust manifold modified /ported by Gregg Gessler- he is out of that business now, but it increased the outlet on the cast iron manifolds.
Problem is the TA downpipes are still 2 1/8 (?) into 2.5" . My engines are not max build ups, I used the TA 212 cam; ran well with GREAT torque.
 
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