i have read that the the RB30DET in 38 mm taller n i was wondering if it would cause any problems in a 240z , and if it does wat can i do to fix the problem

thanks

Unless you have exceptionally low engine mounts I cant see any way around it, however a user here RB30-ZED i think, has done it using the OEM crossover plenum.

My solution on mine was to use an aftermarket front facing plenum.

Can be done without too much drama.

need to modify sump anyway & with modified engine mounts (read totally re-engineered) & move engine back 50mm clearances can be achieved such that the RB30ET inlet plenum can still be used & it just clears the bonnet.

It clears, but only just, this was using Drunkenmaster's engine mounts and a 20mm spacer sandwitched between the engine mounts and Drunkenmaster's RB engine mounts,

Intially the mounts sat the engine to low, caused sump clearance issues with the RB20 rear sump, but still had decent hood clearance, as these mounts appear pretty much identical to Castle Maine Rod Shop RB/Z mounts, it might be an idea to use their RB rear mounted sump instead of the RB20 one, as it look as if its flat at the front of the sump, not sloping like the RB one,

However, even with this additional spacer, the intake has about 5mm clearance before it hits the bonnet, so RB30's will easily fit under the hood :-),