Groundbreaker, I'm not sure on the exact year, but it was when Ford took over from Sperry, maybe about 1988. The early TR96_86's had a cat 3208 and later ones had the Ford 474cid truck engine. Early TR97 had truck motor and about 1995 TR97's had a 456cid Genesis engine. TR88_98_89_99 all have Genesis in them. Good motors. Ilnewholland