Hey Guys, Do any of you know how to positively I.D. Vortec Heads? I have a 350 that has the 1 piece rear seal, center bolt valve covers but I don't have the intake. From my research the best I can gather it that it came from a truck. I haven't been able to find the casting number on any website etc. Will the straight down style bolt holes be the key in indentifying these heads? Any help would be greatly appreciated. I don't want to spend any money on thses things till I know. I can also be e-mailed: teaberry0@yahoo.com Thanks again -Mac

The 96-up 350 L-31 Vortec heads have a different manifold bolt
pattern. There are 4 bolt holes on each head that enter the manifold face of the head at a 45 deg angle. The casting number can be found under
the valve cover. If it ends in "906" or "062" it's a "Vortec head".
Anything else is not the heads you're looking for.
Be aware of "305 Vortecs", cast iron "LT-1's" and "swirl port"
centerbolt heads. They use the same valve cover ,
but are not the "Vortec heads". The cast in "humps" at the end of these heads vary widely,, so don't go by them.