Nissan/Datsun engines are really, really tough things with enormous strength in reserve. They are very narrow bore spacing wise at about 3.8125" between bores, same as a Jag XK-E, but much shallower. There is no more than a 89 mm bore capability if you use a Diesel block, so 196 cubic inches is as far as it can be taken. Largest crank throw I've seen is 86 mm.
The block is longer than the 200 due to the OHC cam layout. The left hand exhast isn't an issue because the engine is tilted to the passenger side. Starter is high mount like the 200 high starter.
The stock Mustang/Falcon/Maverick engine mounts work if you make custom engine mounts. I'm doing some here in NZ for our guys who like the closely related RD28 or LD28 diesels in there because of the high price of gas. All Nissan/Datsuns run similar sump postions, and its easy to swap a 240, 260, 280, 2.8 Diesel or even the RB26DETT engines from skylines.
The main drawback is its very heavy. Even the later RB30E EFI engines with alloy heads hit the 473 pound mark, and the 280 z is even heavier. Cam chains and running low on oil kill the engines. The earlier HKS/SU intake likes bigger SU 2" carbs, and the stock 280 Z/ZX EFI is rather restrictive. The engine loves a big rev up, and is pleasent right over the 5000 rpm range in a way foreign to the 200/250 engines.
The gearboxes are mostly cr*p. Although the Jatco 3, 4 and 5 stage autos are not the best, neither are the monobloc 5-speed manuals. Looked after, there is no reason to change them. The busines I do down here is fitting Volvo/Maserati/Ford Oz BTR LE transmissions to Nissan engines.
The stock V8 crossmember fits the 280 Z/280ZX boxes with a redrill to suit the Nissan mount, and they should be okay.
If you want some details, I'll give you the fab diagrams.
but here goes.
