307 test pipe?

[oxide80]

Looking to pull the cat off my car and put in a test pipe, i found a Pypes Test Pipe and one through Torque Tech (they still have flanges to build a test pipe) so question is will the Pypes or TT flange the right size? They are listed for G Body, but as ive noticed Regal/MCSS/442 all seem to be different exhaust...

 

[307 Regal]

Someone can correct me if I'm wrong but I always thought G body exhausts only differed from the cat back. (after the cat I mean.) What I do know is that the "dual exhaust" systems split after the cat. And then there's my car's stock exhaust where they faked it with a dual exit muffler, which I assume had an identical mid pipe as the single exhaust cars. But as far as the cat I assume GM would've just used the same one across the board for simplicity's sake. I can't give you a solid answer.

I do know that when my dad and I "added a test pipe" to mine (grafted in a piece of pipe from the auto parts store) it completely changed the sound of the car. I had put on a Flowmaster 80 series prior to that and the car literally still sounded stock until we removed the cat. (I actually wanted to put in a high-flow cat but my dad convinced me I didn't need it due to our county laws. Dunno how things work up in Maine for emissions.)

 

[UNGN]

The Pypes flange/pipe is pretty typical for a G-body Cat:

Unless its a turbo car, I'd just put a cheap high flow cat in... and even if it was a turbo car , I'd make it where I could easily swap a high flow cat in/out.

I hate smelling like gas all the time. It can't be good for you.

 

[oxide80]

No inspection on antique autos, but law states if manufactured with it is suppose to remain... i will take my chances...

Thanks UNGN, i was thinking that the cat flange was the same but not certain, i just noticed the 4 bolt flange is either on the front or rear depending on model. If i get gas odor i'll reinstall the cat