I need to find a set of downpipes for my motor. It's a 1970 455 Olds out of a Delta 88 Royale. Has manifolds/flanges only so it's pretty darn loud. This motor is powering my 54 GMC 2 1/2 Cargo truck (Deuce and a half) so I don't need anything fancy. I believe they are the type of manifolds where one downpipe bends around the front of the block and connects to the other downpipe. I'm real handy with my mig welder and if I can find some 90' 3 inch pipes can I just weld them onto the manifolds themselves? I have lots of room to play under the chassis in this thing, ground clearance is well over 2 feet in most areas. If I can run both pipes straight back, weld 2 glasspacks on and dump them at the middle axle i'll be happy. Would be a simple 4 piece exhaust system.

 

Try one of the mail order sites - look for a 'universal dual exhaust' kit!
Shoud be reasonable and work well!

 

Make a pattern out of cardboard, take it to you local muffler shop and have them flare the ends to the manifold and bend to fit you pattern easy peasy

 

If you are asking about the downpipes that run from the manifold outlets to the mufflers, you will either need to have them custom-bent or weld them yourself. Walker actually sells flared sections of pipe. Make the guy at the parts store pull out the paper Walker catalog and turn to the accessories section in the back. There are downpipes made for the A-body cars with the W/Z manifolds (Pypes Exhaust, for example) but if you are using the manifolds from the 1970 Delta, these downpipes won't match up due to differences in the outlet locations.

 

Thanks for the replies, I like the cardboard idea! I also found this set of headers online last night. At $120 it's a steal and I don't need anything fancy by any means. Will they fit okay?

http://www.summitracing.com/parts/BIG-11154FLT/

 

" Make the guy at the parts store pull out the paper Walker catalog and turn to the accessories section in the back."

Love that Joe. I have to find the part numbers for them myself and they still send me the wrong parts. seems that if you have anything other than a honda with an oversized exhaust tip they are clueless on how to find parts.

 

They will bolt to your engine. We have no way of knowing if they will fit your truck or not.

 

I dont know if those long tube headers would fit. I bet you would have better luck with some block huggers if you dont have the front crossmember. http://www.sandersonheaders.com/Sand...obile-455.html

 

A little out of my price range! It seems Summit allows returns on unused items. I'll probably order them and "try them on" (won't "use" them) and if they don't fit I can always get a refund. There is lots of room under there to play with and I don't see anything that could get in the way of them fitting.

 

Come to find out my engine has TWO left hand manifolds on it! I will be getting my hands on a pipe bender so I am going to make the exhaust myself.
Will having two left side manifolds create any problems? It looks like all I need to do is switch them and they will work fine. I believe one is a pre 1970 manifold and the other is a 72 manifold. Yeah, this was a junkyard engine swap for sure.

 

Campbell's Soup Can.

 

No harm done but this thread is over 12 years old and the OP hasn't posted since January 2012.