I've got a GM small block crate engine, the basic 290 HP version, in a 1980 Corvette. While I'm preparing the car for another season of cruising, I'm probably going to change the plugs. The engine is stock except for the RV cam. The quad jet is still in place but the car has "hugger" headers and a 2.5" dual exhaust. The HEI ignition is still being used.