Wow! All I know is it was a stock engine with no changes. It was a 1/2 ton stepside truck. I still have the truck. I was able to get a complete 350 FI GM engine/ plug and play for the replacement. I do also have two long block LT1's, 94 and 96 year w/o FI if I need a fall back due to the possiability the Vortec is bad. It was over heated causing the replacement.