I used Don's Custom Exhaust in Ohio, for pipes on my 383 GTS. My car has the stock Ex manifolds, and he custom bent and shipped me the correct headpipes and tailpipes In 2 1/4 for $520. I bought 2 Dynomax Ulra Flows for $75 each. My hangars were good, so just neede to get some clamps at my local Parts Store. Easy Peasy
Don is HIGHLY CapableI may have to find someone locally that's more capable. The last time I did that the tailpipes rattled against the gas tank and the fitment of the whole system was off. So I'm a little leary of going that route again.