I have an '80 that I put a true dual system on from Mid America. I also have headers so I had to modify it a little. The kit works great for the price. I topped it off with Flowmasters and couldn't be happier. The only thing I'd like to do now is work in an "X" pipe.

Stick with the 2.5" To big your torque will suffer. The headers, piece of cake. Check out the chambered exhaust system from Mid America. It's a little restricked but sounds great and you cant beat the price.