I have an 87 Gt and I am sure this part will fit, but the 87's were R12 and I am going with R134A, since I am replacing the condenser, dryer and all new lines. I know the pressure settings were different between R12 and R134A. So will this work with R134A.
Out of the box, these are set for r12. Inside where the plug goes, there is an adjustment screw. With your gauges hooked up, most will turn that screw till your running about 30psi, and its good to go and will function properly.