You don't NEED the R154, but it's a good idea if you're going to go for upgrades.
You will need to do something about the tach. You can get the box from a turbo car, or something like a MSD tach adapter. There's a list of resistors you can swap if you're handy with a soldering iron as well.
Of course you'll need the goodies that come with the GTE as well, like the igniter, injector resistors, and a few other things under the hood. Probably best if your donor engine (At least the ECU and wiring harness) come from the same year of car that yours is, but it's not impossible to make it work if it's different.
If you swap out the transmission, you should swap out the differential as well. You will need to swap the driveshaft for the transmission. If you're in Canada, you'll have a 4.300:1 limited slip differential already. If you're in the States, it will probably be an open differential, though it MIGHT be limited slip. I'd suggest that you swap out the differential. An '88 turbo should have a 3.909:1 limited slip, which will make a 10% difference on your speedometer. (I ran the turbo diff in my NA for years, so my odometer reads quite a bit low.)
Other things like intercooler are a good idea, and some instrumentation. Don't bother with the factory boost gauge, go aftermarket. Leave the voltmeter in there!
