Quick question for you automatic guys. I have the chance to score a donor car. A 98 Buick regal GS. 3800 series 2 supercharged with the HD trans. The engine will be used for my Fiero swap but my question is will the HD trans work for an 05 Monte Carlo with a standard 4t65e transmission. That car has a blown transmission and was wondering the possibility of using that transmission on the Monte. Thanks for your help

The 05 will have different wiring than the 98.
I think the gear selection switch is internal in trannys over 2003
The only thing that is HD on an HD is the differential.

The GM 4T65eHD design was changed by GM in 2003. The electronic signals that shift the later transmissions (03-up) are different and the 95-02 PCM's cannot shift them. . The 2003 PCM can be used to control your powertrain combination. It is the only GTP PCM that can control a cable operated TB 3800SC and shift the later transmission. Your harness must be based on the 2003 Grand Prix 3800 engine. AShould you not want to build that harness yourself; a number of forum members here can build that harness for you.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Ahh gotcha...not just a simple swap I see. Well if anything it'll still be a good candidate to complete my 3800sc swap. Thanks for the help