Only made R32s as GTST4s, 33s and 34s we're non turbo GTS4's.

GTS4 and GTR boxs are all strong enough, as are the diffs.

RB25 internals can take 600bhp with no mods if mapped right.

Turbos are usually ok at a bar.

If its got a MPH convertor that goes between the gearbox drive and engine, throw it away, thats what makes 4wd skylines so tailhappy and not like a 4wd at all, esp R32GTRs (basicly tricks 4wd system and makes it poo, when you doing 100mph it thinks its doing 100mkh, ie 62mph, so the 4wd acts differently, not as much, and then you go backwards into a ditch )
Worn transfer boxes dont help either.