[gmachinz]

This is a pic of my 86 w/factory engine oil cooler setup from a 1990 Suburban. I haven't seen a GM style one for a 73-80 truck but maybe this gives you an idea. The aluminum lines have crimped hoses and they route to a sandwich adapter above the oil filed and have (2) 45-degree fittings in which the lines thread onto. Fel-Pro is the only company I know of that offers a universal o-ring repair seal kit for these GM style adapters. If you find one, I'd suggest rebuilding the sandwich adapter seals.