u can pick up the unit its self if u wait around for 1grand and i think the ba's still had enough room to fit the bastard in so not alot of modding otherwise if its cut out for the tiny 4speed then yeah big job but it will make the ratio of your gearbox more competative whith those of holdens and what not( holdens and there 1stgear) 4speed has bad as ratio unless your boost comes on early u will need them diff gears or stally
you should speak to henrich performance and tunning cheap and does the best work he got my na 6 to beat stock ba xr6t's he only charges labour never on the part its self, and he dyno tunes everything until he thinks its perfect
hes at lonsdale btw