Hey Mike. Acording to my fine 1992 Jimmy-Sy-Ty shop and service manual series, our trucks have the same iddybiddy 10.5" rotors and 9.5" drums as any other GMC S/T vehicle, plus we have the 4 wheel anti-lock equipment which seems odd with the big tyre and tiny brake combo?? I'm in process of rebuilding my Ty brakes: using Porterfield Enterprizes (800-537-6842) carbon-kevlar street pad/shoes, and still shopping for stock dimension upgrade rotors and braided lines. See "BRAKES" in this section. If you upgrade to larger diameter disks and non-stock calipers, be advised you may run into fitment problems with your stock wheels. If you find something newsworthy about brakes let me know? PS: If you don't have the shop manual series especially the Ty-Sy Supplement X-9276, you should. Get books from GM dealer, or on CD from Sportmachines.com
