I just went through this regarding ID-ing a Vortec engine. I saw a lot of adds claiming they had a Vortec for sale, only to find out they had a TBI, not a Vortec. The Vortec will have 8 intake bolts, and they came with 2 different head castings, 062 or 906 (they are basically the same). Not sure that this helps you, but a big difference in performance between a Vortec and a TBI.