Does anyone make dual exhaust manifold downpipes that will fit a G Body with SBO? My car is a very original 1980 442. It still the original single cat exhaust with dual outlet muffler - way too quiet and restrictive. I will install the block off plate on the affected manifold.
Thank you,
Shiftydr

 

Others have used the BBO Pypes down pipes with success.

 

I used the Pypes 2.5” stainless downpipes and they fit fine. I did dimple the driver side to give a little more clearance to the control arm attachment bracket, other than that that fit fine. I read on another board that the exhaust manifolds from big to small block Olds are different but the downpipes are the same from one to the other.

 

Thank you gentlemen! I have heard that the Pypes downpipes might work, but I wanted more information before shelling out the $180.00 on a chance. I already have a double hump cross member and Dynomax header back exhaust with Cherry Bomb Salute mufflers. The Dynomax pipes are only 2.25”, so I’ll have to weld in reducers. I’ll try to record a before and after for posterity. I think that should help wake up the otherwise stock, original, Olds 350.

 

It will make a very noticeable difference. A guy with the 85 442 gained over a second in the 1/4 mile by just adding dual exhaust. The 307 HO cat back dual exhaust was definitely better than 80 442 exhaust.

 

These will work:
https://www.pypesexhaust.com/product...-2-bolt-dof10s

The fit isn't the best you might need to do some clearancing (smash with a hammer) to get around the starter on the driver's side. I reclocked my mini-starter out of the way, but a stock starter could be a little too close. I don't like how low the system hangs; IMO it needs to have some tubing cut out and re welded to tuck the exhaust closer to the car. It's not unacceptably low but a little too low for my taste (my car is lowered so YMMV).

I have them on my car (85 442) with this system:
https://www.pypesexhaust.com/product...-exit-includes