will be trying to fire up my 455 in the coming weeks and im working on setting up a temporary exhaust system .i have a bunch of left over stuff from my other cars so i was going to set up a single exhaust with crossover pipe .i believe i have a right side 455 manifold and left side 350 .what exactly are the differences between the two ?and is there a way i can identify the numbers on them to be sure what i have ?thanks

 

If the set up is temporary it shouldn't matter, The bolt holes are all the same, the 455 will have a slightly larger port opening than a 350.
Hope this helps, Good luck

Johnny

 

Back in the day I put a Olds 350 in a 1968 98 which had a 455. I went to hook up the original single exhaust pipe up to the manifold and found they didn't match but all I had to do was elongate the holes on the flange and it bolted up and never leaked. Amazing how that low compression 2 bbl 73 350 lugged around that barge. It was my winter beater a couple years. I was the only guy around with a 455 Olds in a Omega and a 350 Olds in a 68 98. Good times... Keep us posted on how your engine runs.

 

As with cylinder heads, SBO exhaust manifolds have ID numbers, BBO manifolds have letters. The SBO manifolds are more restrictive, which won't hurt anything for a temporary installation.