Hey guys just received my new dynomax cat-back exhaust for my 83 z28 part #17495. This thing looks great but I do have 1 question. I guess I assumed this would bolt up to my factory catalytic convertor but I don't see how. I have a factory cat that has a rectangular end with 4 bolt holes. I am guessing I need a different cat but am not sure which one will work with the factory y-pipe and the new exhaust any steering to a cat and part #'s would be great thanks...

 

I had (have- difficult to do car work while deployed) a similar issue with the 4-bolt flange (the square part with the four holes) and a catback with a smaller 2-bolt flange. Got with the muffler shop for some help and they said they could either weld a fabbed 4-bolt flange onto the catback or just cut off all associate flanges and weld the catback to the cat.

Might be easier than trying to mix & match pieces that will fit together out of the box. I remember seeing a 2-to-4 bolt flange adapter somewhere but all online sources seem to be out of stock as nobody manufactures the piece any more.

 

Why not replace the cat with a better flowing one? Worth it for only a $100~.

If you want to keep it, I know something like this would work.

http://www.summitracing.com/parts/WLK-35685/

Just look around, I just typed 4 bolt flange and it came up. No idea but if you found out what its called im sure you can find a adapter for it.