You don't have to take the engine out to install headers...who was the deededee that told you that?

And stock...until you get mods. Intake, 180* T-Stat, Autolite 104 spark plugs, New Wires of some kind, Tuned PCM of some kind, Front Powerlog, 3" Downpipe and U-Bend delete and you MIGHT get away with a 3.4" pulley.