Street Fire Distributor MSD5591Street Fire DistributorGM EFI, 1988 95, All new components, Heavy Duty Gear MSD5591 D5591 GM used this distributor when trucks first moved to EFI back in 1988! It was carried over into cars and was used through the mid 1990's and the introduction of the Vortec engine and the LS Series block. Also, many aftermarket EFI systems require this style distributor and module.