Wilwood's D154 forged billet caliper is a direct bolt-on, lightweight, high-strength, extreme duty alternative to the OE cast iron calipers that were used on a wide range of factory disc brake equipped mid size GM cars and small trucks beginning in 1978. Use of this caliper can still be found on some GM models as late as the year 2002. The wide spread and affordable availability of D154 calipers and brake pad compounds also made it a popular choice in a number of restricted class competition categories and drum to disc conversions on all types of hot rods and street machines.