The 2.8 liter GM motor for the 1985 GMC S-15 uses a filter thread size of 18 x 1.5mm and O-ring size of 2-3/4 inches. The Derale Remote Engine Oil Cooler Installation Kit, # D15751, has multiple thread and O-ring sizes including the ones needed to install it on your S-15. view full answer...
To install a 4-way on your 1984 GMC S15 Pickup, you will need to hardwire a connector like Draw-Tite 4-Pole Hardwire Kit, # 18252. Just use the included tester to locate the vehicle's right turn signal, left turn signal, and tail light circuit. I have included a wiring chart and install video for you.
Part # C55312 is designed for the 1985 to 1990 GMC S-15 pickup so this would not work for your 1984 model. view full answer...