Engine and transmission compatibilty (Page 1/1)
tater85 SEP 30, 12:36 PM
I have been looking for donor vehicles or considering junkyard sources. I decided that the 4t65e-hd is going to be the transmission of choice for my 3800 swap into 86 4 speed.

I can't seem to find conclusive information on transmission year compatibility. I have read that series 3 transmissions need to be used with an 03 gtp pcm/ecu. Is this true?

Does the transmission have to match the engine year or the ecu? I know the transmissions have some differences. Please school me on what I need to know for donor compatibility. Primarily looking for series 2 w body gtp regal or 04-05 impala, due to correct oil pan, filter extension and cable throttle.

[This message has been edited by tater85 (edited 10-01-2023).]

Dennis LaGrua SEP 30, 04:34 PM
This may help.
You can use the 95 to 02 transmissions with a PCM that has supported that time period. In 03 GM made a transmission change and the new PCM put out different shift signals. Should you wish to use a cable operated throttle body you can use the 03 PCM to run the engine and shift the 03 box.
The later 07-07 3800SC's use the same later transmission but the PCM's are set up for "Drive by Wire" and use a servo motor ( electrically controlled) throttle body. For those swaps you will need to add the throttle pedal module , a fuel pressure sensor and the PCM operated single line fuel pump. A few other changes are required

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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, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "

tater85 OCT 01, 02:42 PM
If I use the northstar TB and a 2003 pcm, I should be able to make a engine trans from a 2007 donor car work right?