If you need a swap harness that is neat, clean, uses no splices, fits great and looks like an OEM unit. Try Phil Dull at Injection Technology out of Little Rock Arkansas. 1-501-216-7350. A couple of other guys make them and they work, but AFAIK Phil is the only source that supplies an all new harness. FIerrog also makes excellent stuff but again there are other 3800 swap mount sources as well. All of the ones that I have seen installed look excellent.
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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 "