Cool car, worth saving! I agree with Mark, just replace ignition with the kit bypassing the feedback computer that is up under the dash on the driver's side. Then a new or rebuilt non feedback carb. Try and find a "canadian" y pipe and dump the pre-cats and main cat. You'll have to plug some holes where the air pump/tube to cat were. These alone made mine run really nice! Eventually you could do dual exhaust. I got the A body kit from Jegs. 2.5" mandrel bent. Shifted my tank over (pretty easy) and extended the filler tube and the exhaust tucks under there real nice with some minor mods.
My guess is that your frame is good. Might have some floor or trunk rot from water flowing top down.
