Small block exhaust manifolds

jhodgson

New member
I just learned something that might be useful. I am reinstalling a 1968 350 in my 1968 Skylark. I am using the 2-1/2 inch TA Performance down pipe. Due to other modifications, I am not using the stove nor the heat riser valve so I gutted the valve, plugged the shaft hole and bolted it to the flat flange on the bottom of the manifold. I did this because I needed the nipple on the bottom of the heat riser valve to accept the female flare on the top of the TA down pipe. I have another 350 laying around that I should have looked at sooner. Its blue with HEI and lots of emissions stuff but I don't know what it is out of. Anyway its manifolds are made opposite the 1968 versions. The left hand has the flat bottom flange and heat riser casting number B-1246669-1. The right hand is slightly longer than the 1968 version and includes the male nipple as part of the manifold casting number B-1246656-1. It would have made a cleaner installation had I used this one on the right side of my 68.
 

jhodgson

New member
350 manifold

True. 350 only. I believe the other small blocks 215 thru 340 use a different head layout with equally spaced exhaust ports. Not Siamesed on the centers like the 350.
 
yeah, they're actually siamesed on the center intake runners. their manifolds have a very "header" look to them.

i normally refer to those as "Rover style".
 
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