Engine wireharness confision 88 vs 89

[Supra Saiyan]

So this is simple, but I keep getting confused.. I know that an 88 a/t engine harness wont work right on an 89 a/t engine harness..
My question is that.. What if it's a m/t harness from an 89 going on with this a/t engine / transmission..? I feel like I am talking myself in a circle because ive read so much..

BTW I am speaking of a turbo engine harness during this entire thing..

So what else will I need? I don't want to replace the gauges and such as well.. Will I need to do some things with gauges? Will I need anything different.. Or can I just get the 89 harness and the engine and plug it all in..

[cre]

Here's the breakdown:

GTE:
5spd may use either a 5spd or an auto harness from that same revision (ie pre89 or post89)
auto may ONLY use an auto harness from that same revision (ie pre89 or post89)
Using harnesses from incompatible generations of GTE is, fortunately, not an easy affair as all of the primary plugs are physically different and won't fit and/or missing... so all you need to concern yourself with is what year and what type of tranny.

GE:
Same as the GTE but for different reasons... while the pre89 and post89 GE harnesses may interchange there are differences in the electronics of the EFI system which may cause significant damage should you try to interchange them; The primary difference is the lack of the fuel injector resistor pack and the use of high impedance injectors in the 89+ revision. The ECU side connectors for both revisions are the same shape but are a different color; If the colors don't match the socket on the ECU side it IS a problem.