Magnaflow just used our 1980 as a "test mouse" to design a system for the 80-82 vettes.In exchange for them using the car  they put a complete system on our 80. It sounds Great!! I don't know if I'm allowed to post a link to pics of my system but you can find them in my Home page under Vette Miss Doug Mariani2008-08-27 14:13:32

On "BIGBRRD" we put Heddman shorty headers, an X-pipe from Pypes, and Flowmaster Delta 50s.  Haven't had it on the road enough to know if it is going to be too loud inside but it has a nice low rumble at idle and barks pretty well when the long pedal is stomped on.  Also seems to have more low end grunt than before as it is awful easy to lite 'em up...!!! 

I have the Hedman headers with Flowmasters and the X-pipe just behind my transmission. The sound is great (loud). The perfomance is also great. However, with the X-pipe you will loose some sound as compared to straight pipes or H-pipe. But the advantage is the gain in horsepower. That is the reason for the X-pipe existence. Horsepower wise all tests that I have seen comparing the setups give the nod to the X-pipe. Before I put the X-pipe I ran straight pipes. Personally I would not go back to either of the other two setups. I do get some drone at times with low rpms. Therefore, I just try to keep my rpms at a higher level. I have the close ratio 4 speed with a 3:36 rear end.