I have a 1991 Chev V-3500 Crew cab with the 6.2 Diesel, and the earliest 4L80-E known. I tow a fifth wheel 32ft. I lost 4th, 3rd, then reverse. I am trying to find out if I can get a surplus transmission from the army. same transmission as the 6.2, 6.5 humvee. does anybody know where to look?