"Strato-Flight" was Pontiac's name for the Hydra-Matic transmission. It's a 4-speed automatic with direct drive in 4th. gear and a fluid coupling, not a torque converter. The parking lock is engaged by puting the shifter into Reverse with the engine stopped. The Pontiac V-8 was used as original equipment in GMC trucks, not Chevrolets. Tubular headers are usually good for raising the underhood temperature, leaking exhaust gas at the header-to-cylinder head gaskets, and burning spark plug wires. The only place they give a measureable power gain is at high RPM, so unless you're planning to do a lot of full-throttle running, I believe the problems aren't worth the gains.
Jerry