Greetings,
First off, welcome to the forum. 🙂
Second, are you sure its a 305 and not a 307?
The 80's Cutlass's came from the factory with a v6 or a v8. The v8 was a Oldsmobile 5.0 liter 307 cubic inch engine. Unless it was a canadian car, which DID come with the Chevy 5.0 305 engine.
Summit racing has kits listed for the dual exhaust from the cat back, just as the factory 442's had.
Is there something specific you had in mind for your car? Price range? True dual or cat back system?
Let me know and I will try to point you in the right direction.
