I rebuilt my 1996 330hp 454 from last year and it is now a 496 with about 525hp. Question: I was reading that the thunderbolt v has an over-speed control on it, is this the same as a rev limiter? if so i assume it will be a low rpm due to the 330hp engine.

you will need the mag module otherwise your limited to about 4750. $470 on ebay

That would make sense, i did a cam, heads, exhaust and carb change last year and i didnt get any more rpm. New distributor it is..