My last truck was a 88 F-150, I had 6" of susp. lift on it, never had a problem with the driveshaft lenght's, but i did tear a rear one out once, when I was playing tug-a-war. Go with the stockers until you get the money or tear on out. My front had a slipyoke on it with a boot around it and it seemed fine. It lasted 4 years until I sold the truck.