i have a 1985 trans am with the lb9 305tpi. it has bottom end probs and was going to fix the motor but have the opportunity to purchase a l98 complete with motor computer and wiring harness out of a 87 or 88 iroc for practically a steal of a price. now my question is would i have to repin the fuse box plug (is it the c100?) im talking about the connection below the master cylinder?

 

The left bulkhead connector may just be the same. If not, its easy to swap yours in. All it is for is, half of the connector is the headlights and makers and horn and such so it would stay with the car.
The other half is for the signal to the gauges, starter, power to the interior, coil power.
The computer harness is pretty much by itself and all goes through the firewall from behind the right fender.

 

i guess what im asking is can i just drop the l98 into the 85 and will the gauges work properly or will i have to change the wiring around for them?