I don't know if you wanted to change the final drive gear/axle gear ratio...don't think it so easy but if you go to vividracing.com and a few other places have gear sets that will give you a closer gearing and probably a bit tougher too

 

Gears aren't the weak part of the tranny, it's case flex that causes problems by letting the internals get misaligned. Also, please try to post techncal questions in the proper forum.

 

i called rally spec and they told me you can get a couple different kits.. one was the sti ra 5mt w/ stock case and diff for about 33 hundred and its got a 500 core return i believe. you can buy just the gears with the input shaft that will fit directly in your case for about 28... so id just go with the case swap and return your old tranny once its out.. its almost the same price and its a rebuilt sti ra gearset with diffs. although these gears are not too much stronger than stock (15% stronger or at least thats what they say), they have a much better gear ratio for competion.

 

STi RA gears would be perfect, but expensive. You could do an RS gearbox swap instead. Very cheap and you'd have much shorter gearing. It is about as strong as a WRX gearbox as well. Best of all, you'd still haev your stock gearbox if you broke the one you got to drag race.