MSD Distributor Vacuum Advance fits GMC 1987 R1500

MSD Distributor Vacuum Advance fits GMC 1987-1991 R1500 Suburban

MSD Distributor Vacuum Advance fits GMC 1987 V2500

New HEI Adjustable Vacuum Advance Fits all 6 & 8 Cylinder HEI Distributor

MSD Distributor Vacuum Advance fits GMC 1987-1991 R3500

MSD Distributor Vacuum Advance fits GMC 1987-1989 R2500

MSD Distributor Vacuum Advance fits GMC 1987-1991 V3500

MSD Distributor Vacuum Advance fits GMC 1987 V1500