hi, ive got an astra sri which is a 1.8 rite, my gearbox is knackered and wanna get a new one.

i think the one its got at the min is an f16 close ratio jobbie.

can i put an f18 or f20 on or would i need a 2 litre for it??i want the best possible acceleration from my gearbox but dont want a weak one that'll f*ck up again a few months down the road.

what do u guys reccomend i replace my old one with??