[750hp]

Welcome to the forum! If you're used to having an overdriven 5th gear, it might be a step backwards to choose a single rail or toploader 4 speed. On the other hand, I f you're happy with how the car feels on the highway in 4th gear, a toploader might be an option.

Your budget might determine your choice. A steel case Toyota box will be a less expensive 5 speed option than a new TKO 500 or TKO 600, but won't be as strong.