Hello everyone. I’m looking for a 1984 Fiero engine harness and a 3800SC engine harness that will work with the 3800SC that came out of a 2001 Buick Regal GS. Not sure if the year and car it came out of matters or not. If anybody has any tips or instructions on how to build the harness for a non A/C 84 Fiero manual, please share any tips and tricks. Many thanks in advance.

You can purchase a stand alone 3800N/A or SC MT stand alone harness here for $319, about $79 higher for auto. Then you would just need to keep the Fiero wiring in place for the gauges, BU lights, and gauge sensors. Should be a simple hook up.
3800 stand alone wiring harness

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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 "

Thanks Dennis. I’ll check it out. I appreciate your time.