You should be concerned about retrofitting a turbo to that engine if that was part of your plan. Compression ratio too high, and pre-1988 engine uses the skinny connecting rods.

What do you mean 'wiring loom' issues? ...you cannot use any of the 1986 electrical, including sensors or fuel injectors. You can, however, leave the block mounted distributor and install a long enough coil wire to reach the cap. Be sure that the block has the holes drilled at the top of the bell housing area to hold the crankshaft pickup as you'll need to use it on the '91 car. Be certain to mount the '91 flywheel corectly or it will not start. At TDC, the 'missing' hole should be in line with the starter opening.

The turbo fuel injection system will run fine if you drop that engine in without a turbo as part of the system, so long as you keep ALL the critical parts that belong to the '91.