my gearbox is leaking oil, so i need to get it out and fix the damn problem.

a vriend of mine can take the gearbox apart and replace all the parts i like.

my s2 escort rs turbo now has 140 bhp, but it will be tuned to 230 bhp (1,1 bar) within half a year (atleast thats my aim).

can someone please tell me what parts i need reinforced, so the gearbox wont die when I have this amount of power ?