Temporary exhaust system

I may go with the setup you mentioned, but headers are a definite no. Everywhere I've read the "budget" headers are a PAIN to install on A-bodies, and they almost always hang too low. I'm not going to think about headers until I do that nice 360 Magnum/4-speed swap in the future. I think this is what I'll do for now: Get two lengths of 2" or so pipe for cam break-in, then re-install stock single exhaust with maybe a cheap loud muffler. Then I'll get the Pypes Race-Pro system and use flex-hose to make mock-ups of the downpipes I'll need, which I'll take to a muffler shop and have fab'd from 2-1/4" pipe to mate better to the stock manifolds.