gearbox and final drive options?

[mini64]

Would someone be so kind as to do a gearbox and final drive summary. I search this site but these keywords are so common I end up falling asleep before finding useful info.

I have the semi-close box and a 3.777 final drive. I run the car at a track where I hit 7500rpm at the end of the main straight. Am thinking of taking it to a track with two longer straights (Road America) so am a bit worried. I see there is a 3.5 final drive available, but havent found anyone selling one. Maybe I should finally get a better gearbox (always weaing mine out, just recently chewing up 3rd gear), so maybe consider a 5 speed with an overdrive? I just dont know the options or sources.

[rgh0]

If you have a standard bottom end 7500 rpm is more than worrying it is close to a major blow up sooner rather than later.

what mods you do depend on, originally preferences you have, how much money you want to spend and any class limitation in series you run in. 3.5 diff , bigger dia tyres / wheel combo, steel bottom end with higher rev limit, 5 speed box of various kinds are all options

cheers
Rohan