Unknown Cam

Find out some more about the cam before you start to determine what kind of converter you want to buy...but buy a good one the first time suited to your needs. Off the cuff, I'd venture a mild purple cam in a 383 should benefit from about 2500 worth of stall, but keep in mind, the engine's powerband (torque) will play a role in where the converter actually stalls, and how high it will flash.

All that being said, if you're planning on tossing on a set of aluminum heads, I'd recommend you let one of the gurus on here go through them before just bolting them on...several folks on here have had issues out of the box with guides too tight, inconsistent spring installed heights, leaky seats, etc.

Also consider some chassis/suspension mods...having power is nearly worthless (except for demonstration) without being able to put it to the pavement.