im on the hunt for an exhaust system for the 1976 cutlass supreme .im installing the w/z manifolds i got from fusick olds i would like to go with 2 1/2 pipes all the way back ,but it looks like the thortons accept a 2 inch pipe .any suggestions ?and should i order for 73 cutlass or any a-body car.some of the pics of downpipes ive seen appear to start at 2 inches at the flange then expand to 2 1/2 .thanks

 

I would open the outlets up slightly, I think the BBO manifolds are 2.25", maybe that is an option. The Pypes down pipes are supposed to fit, just tie into one into one of their A body exhaust system. You can see that start at 2.25" and go to 2.5". https://m.summitracing.com/parts/pye...s/none/images#

 

thanks i ordered thier downpipes and a set of mufflers

 

If you have not done already you will need a 73 74 A body trans cross member (dual humps) if I am recalling correctly that 75 and later had the single exhaust catalytic converter one.

 

Yes thanks Gearman I did get one and installed it . just finished putting the manifolds on ,went smoothly except the rearmost driver side bolt ( was tricky getting at it)

 

just received the pypes dof10s downpipes .they will not fit unless modified.the flange has so much slop in it that if it isnt perfectly centered on the male end of the manifold it will leak by on one side. . if you get it perfectly centered it isnt anywhere near the hump in the crossmember.so it will either need to be bent to fit properly or returned and im not sure anything else i get will fit ant better.thinking about welding the flange square to the pipe and bending it where it needs to be !if the hole in the flange werent so large it may have worked .

 

i should have mentioned this is on the drivers side .the passenger side appears like i can make it work

 

Just to update I put together the pypes sga30 system last night. It all fit nicely . Waiting for nicer weather to bring it to the shop and correct the misaligned downpipes.