Mega bump and my first post in maybe 5 years but yeah Robbie Ward is right, they are wide as hell being twin cam and all, but they do fit. Google Ian Fournier.
I've got a high comp atmo VK56 in my R32 sedan drift build.
The tightest part was the clearance between the strut towers and the exhaust ports.
Ended up putting in an S14 steering rack for better clearance and getting a custom steering column made to change the angle on the universal to give more room.
Also ditched the brake and clutch masters, running a floor mounted pedal box with remote reservoirs instead. That part isn't essential but I wanted to mount the engine as far back in the engine bay as possible cos racecar.
Custom tunnel etc. Got photos if anyone's curious.
Putting one in an R34 would be fairly similar I would imagine, but forget AWD, if you wanna go big get one of robbies 4wd RB30 long blocks. Be way cheaper in the long run.