1966 273 v8 cam suggestions and exhaust too?...it will never be super performance but

Isky E 4 cam is close to the 66 Hp 273 cam. Just a little lope and a good runner for a stock motor. I put the Accurite LTD exhaust system on mine. A nice fitting single system like the original. Egge has low and high compression pistons available as Rumble stated. You may be able to have pistons made by contacting different manufacturers. I built my 273 a few years ago and it is a good runner, very dependable, and is fairly economical to run.
Check out my build thread. tmm