I'm still not sure how to go about running my gauges off of the '98 ECU, though. Is there a way to go about that, or would a different gauge cluster be a necessity?

If the HPT would work out, that'd be a great option, though. It'* still cheaper than buying a standalone TCU.

You won't be able to run the gauges off of the ECM, that'* why I said you would need manual gauges from like autometer and make your own dash. You would need to add a check engine light and wire in the OBD2 diagnostic port so you could talk to the engine. As far as a speedo I think they make one that works off of GPS and doesn't need to be connected to the car.

the problem, with the oem gauges for your GA or aftermarket ones is you need to find a place for the sender, normally the holes in these have a sender it needs for the pcm. thats where the ease of obd2 comes in. with a 25 dollar obd2 to bluetooth adapter and a 5 dollar app(torque) i can see speed, tach,etc, and setup a gauge in the dash mode for any of it, trans temp, slip, knock retard for tuning, whatever you want. and you can use your phone or a cheap android tablet, have seen a bunch from 50 bucks this time of year.

HPTuners won't touch anything below 1997. And it won't do anything with gauges.

ecm, wiring and everything will be 98

Here is a engine swap company and pc programing company I think can help you.
They show lots of engine swaps on there pages
from a Fiero to a 1988 park ave with a supercharged eng trans swap.
To even tap shifter auto added out of a grandprix in to a Fiero
and lots of other eng trans swaps
Sinister Performance, LLC.

I'm not really interested anymore. I got the Bonneville now and sold the Grand Am to my brother, but the Bonneville is a great car.

the bonnie is better than a ga in about every way

Are you going to swap a 3.1 into the Bonny?

It really is, jwfirebird.. I didn't give it nearly enough credit before, but it'* a sweet car. I love it.