We have done quite a number of engine replacements and 3.1L/3.4/ 3800SC swaps here but have been shying away from them of late. Unless we can hear the engine run beforehand and thoroughly check it out, it becomes a risky proposition. Today these power plants are OLD engines and used one's are high mileage usually in worn to worn out condition. Whoever does your swap, consider putting in a new 3.4L crate engine or a remanufactured 3800 done by a reputable rebuilder.
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "