I just bought a 78 f150 4x4 with a blown c6. (was out of the truck when I bought it) I picked it up from the shop the other day but need to flush the cooler before I put it back in. is there a solvent I need to use or just use fresh fluid and compressed air? was also wondering about adding an aftermarket cooler is it benficial on these trucks? it will be used mostly as afarm truck so possible lenthy idle times and periodic hard use towing, etc. thanks