ive got mine sitting way back, approx 10mm from head to firewall, to do this i had to modify the crossmember, i didnt lower mine at all to avoid any steering complications instead i cut the original one down. I cut 25mm i think out of the guts of it and welded a new plate in so it dips down allowing the sump to go lower in engine bay. I also added strengthening braces, good welding required here! With that mod done you will find things fall into place really well, its like the L was meant to be in there

. I also had clearance issues with 120y swaybar and oil pump so made 10mm spacers to space it down. All in all with new mounts it should fit in well. I found that 180zx box fits in the manual tunnel with a series mounts ground off! Oh and one last thing dont expect to get the box off without engine and box coming out as one. I have to lower my engine and gearbox in almost verticle with front jacked up to get it all in snug, bitch to do but ive got motor out in down to 2 hrs. I found it easier to do the conversion with the engine and gearbox together as it is all a very tight fit. But all in all i TOTALLY recomend you put in the hard yards and do this conversion, you wont regret it and the first drive will make all the hard work worth it!