My girlfriend just bought a 76 ghia. It's an automatic, so it just drags ass down the road until you're goin 60, then its got ok power up to 90. I keep tellin her to buy a header and maybe some weber side drafts (she doesnt wanna do a turbo swap), but i know that trannys robbing alot of power. it's not even overdrive, so her MPG gets kinda crappy mileage. so what more modern transmissions could bolt up to her motor. what other parts would need to be replaced(bellhousing, flexplate....)?