ACCEL Adjustable Vacuum Advance - GM / HEI Distributor w / Vacuum Advance 931121 Mileage gains are also achievable

Mileage gains are also achievable with our new optimized and efficient tuning

the 3-Stage High-Performance Filter Kit is built for extreme dust

Speed Tabs are round vinyl stickers that prevent shredding and ease removal of tear-offs

1979-1993 GMC G3500

1995-1995 Chevrolet W3500 Tiltmaster

ACCEL Adjustable Vacuum Advance - GM / HEI Distributor w / Vacuum Advance 931121 Mileage gains are also achievablePermits practically infinite adjustment to both amount and rate of ignition advance. Instantly increases horsepower and throttle response. Provides maximum possible spark advance while preventing damaging detonation or ''ping''. Includes allen wrench and detailed instructions. Vehicle Applications: 1977 1978 GMC K35 1975 1981 Oldsmobile Cutlass 1977 1986 Chevrolet K30 1975 1986 Chevrolet C10 Suburban 1975 1990 Oldsmobile Custom Cruiser 1975 1987 Buick