Howlermonkey

My suggestion of using the N/A crossmember as the best starting place for this was because the turbo crossmember has the engine mount pad on the driver's side 6 inches further forward than on the N/A crossmember which has the mount pads even with each other..........unless you needed that extra room for the turbo hardware.

My mentioning moving the engine/tranny back as a unit nets you the ability to fit a radiator in the conventional location with the rb engine maintaining the 1 inch between the firewall and rear of engine that nissan uses in most every stock implementation of the RB or L series engine.

Moving it back is absolutely necessary on the M30 or you will find the front pulley hits the core support when the engine is even with the flange of the bellhousing while lowering in the inline engine.

The stock vg30 scheme in both the M30 and the z31 has the bellhousing of the tranny protruding 4 inches into the compartment while the stock implementations of the RB and L engines have it only protruding 1 inch in relation to the firewall.

If you look at the any Z car from 1970 to 1983, first generation maxima, and most RB equipped cars, you find the bellhousing only protrudes 1 inch into the engine compartment.

Of course.............moving it back would move the shifter location a bit too far back but that's why I use the shorty FS5R30 tranny out of the pathfinder and swap over the bellhousing from the RB to it when I put nissan inline engines in a car made for a v6.

It also helps combat push at turn in and I'd rather have the extra space in front of the engine than behind it

Luckily, the z31 engine compartment and radiator location allow more room for this but the extra space with moving the unit back allows a stand up radiator netting tons of room up front of the core support for intercooler, a/c condensor, and fans.

I guess I'm just splitting hairs here but I am guilty of leaving no stone unturned in my quests for the maximum performance.