Distributor Vacuum Advance MSD fits GMC 1987-1989 R2500

MSD Distributor Vacuum Advance fits with Chevrolet R2500 1989

MSD Distributor Vacuum Advance fits GMC 1987-1991 R2500 Suburban

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

MSD Distributor Vacuum Advance fits GMC 1987 R1500

MSD Distributor Vacuum Advance fits GMC 1987 V2500

MSD Distributor Vacuum Advance fits with Chevrolet R2500 Suburban 1989-1991

MSD Distributor Vacuum Advance fits GMC 1987-1991 R3500