I've been searching thru the posts and have yet to find a definitive source to buy downpipes for a 350 with stock manifolds. I want to buy the Pypes X 2.5" system but they have everything except the downpipes. It is a showy car so I want some nice stainless downpipes since they can be seen with the hood raised.

I don't mind having to modify the downpipes a little but I need to start with something that is close. Can someone suggest which downpipes to buy???
Is there a system other than Pypes to consider that sells the complete package?

Thanks,
-Lewis
71 Cutlass Supr. Conv

 

I actually think pypes makes down pipes for the manifolds.


http://www.summitracing.com/parts/pye-dof10s

 

The applications tab says these are for the 68-70, or for a 455 that's a 1971. This is what is making this so challenging...finding the 1971 350 manifold option.

I'm hoping someone has done this and can point to one that is fairly close???

 

I just made my own down pipes for my dad's car. Eseentially 68-72 are all the same. 455's sat a little taller so you might have to shorten them up a bit if they hang too low.

 

Give these guys a call. I've heard that their exhaust systems are supposed to be as close to factory original as you can get. They are expensive, though!

http://gardnerexhaust.com/contact.html

If you can't find pre-made down pipes, call the muffler shops in your area. I found one that made custom downpipes and a dual exhaust system for my `72 LeMans. I supplied the mufflers, manifold studs, and flanges. After years of fighting with the Pypes system, I couldn't be happier. When you call them, just ask if they have a pipe flaring machine and can make manifold "down pipes" or "head pipes". If they don't have stainless tubing, see if they will let you bring in some of your own and buy the tubing from wherever you'd like. It might be cheaper than going aftermarket. You don't have much to lose except a few minutes on the phone. Try and call the independent shops first (i.e. before calling midas, meineke, etc).

 

The 455 A-body manifolds are taller to match the deck height (which is why W/Z manifolds don't work on SBOs). The outlet flange for a BBO manifold on a BBO is in about the same place as for an SBO manifold on an SBO.

 

So assuming the pypes system is for a regular bbo they should work for his app. I was under the assumption the manifolds would sit taller since the deck was. Taller but it makes sence from an assembly line point of view to only make one set of down pipes and manifold height the same

 

The Pypes primary pipes will fit, you just have to make a "bushing" to seal against manifold outlet. Basically just a 2 1/4" flange placed in/on 2 1/2" flange to neck it down.

 

I bought the 2 1/2" Pypes exhaust system along with their down pipes to use on my 72 S w/ 350 SBO and it fit fine. A little tweaking on the drivers side but nothing major. I did install w/o the body on which made it easier