Okay, I been at this for a long time, & still I'm not quiting. I got the car running & I gotta say, I'm impressed. The LT1's power in my 1992 Z28 is awesome! I love! Now can someone help me work the bugs out? My gauges aren't working properly. No tach, no speedometer. No oil pressure, voltmeter, engine temp, or properly working fuel guage. With the sensor gauges, the fuses are fine, so steer me elsewhere. Now, what's up with tach & speedometer? I'm running 1992 Z28 with an LT1 wired as a 1995 Z28 backed by a 4L60E with 3.23s at the tail. Also, my shifter is a tad off, it don't go all the way in park. Lastly, I wanna be able to plug a scan tool up in the ALDL port and retrieve trouble codes. Could someone tell me exact fixes for the speed/tach thing, and shifter thing(like what bracket and cable to use). Help, but I love it! After I get the car running with all the kinks worked out; I'ma freak it with an all black interior and leather seats to go with it's metalic blue outer shell. Somewhere down the road I'll probably do an LS9. I'VE BEEN POISENED BY THE POWER BUG! Y'all did this to me, it ain't right, but I wouldn't have it any other way.

 

Speedometer wire from the PCM should be hooked directly to the speedometer wire for the gauge. Get rid of that speedometer cruise control box under the dash (yellow looking thing) and hook directly into that speedometer wire that you will hae once removing the box.

Oil pressure should also be hooked directly into the gauge, at least that is how my LS1 is done. Voltmeter is also hooked directly into the gauge. Coolant temp is also hooked directly into the gauge.

Are you certain you have power AT the gauge cluster?

 

D6 on the c-100 Black/white Tach / Wire to pin d (white) on C230 Lt1
E5 Tan Oil pressure signal / Wire to pin B (Tan) on C220 lt1 harness
F5 Wire to pin K (Dk green) on C220 lt1 harness
F8 Wire to pin A (red) on C220 lt1 harness
Might check to make sure you have them wired up correctly.
The shifting problem you might have to adjust the cable to the shifter I had to on mine had the same problem as you.

 

https://www.thirdgen.org/forums/ltx-...formation.html

Most of your questions are covered in there

Yes, hook the PCM speed output to your speedo wire, but dont go searching for the "yellow thing" as you will not have it. 90-92 V6/TPI cars used the 730 ECM which did not need an external VSS buffer box to split the signal. The cruise box is black and removing it will only disable cruise

Congrats on the running swap