Rb20de mounts

[confusis]

I'm looking @ transplanting a rb20de into my r30 (just gonna be a cruiser).

car: 1982 4dr PJR30 (1.8l carb) TI [L] (luxury )

Mounts issues: My car has the z18 motor. The engine mounts look identical (i could be wrong) to the l20et mounts. The gearbox is a longbox but the engine is quite short and sits basically in the centre of the engine bay with 6"ish room behind it.

will the rb20de bolt straight onto my mounts? what about the oil sump, will i need to modify it? and i'm going to use an automatic gearbox, will this bolt straight in, or will i need to fabricate adapters?

and one more question: would the rb20de be much heavier than my z18?

thanks