regular heads and vortec heads

[topnos]

I do not know if this is the case or not, but I would have to say the accessory bolt holes for a Vortec head and a Non-Vortec head are more than likely the same. However, since I have the 330HP/350 with Vortec heads, I know from experience that I had to buy different accessory brackets for my rebuild when it came to mounting options involving the intake bolts. Here is a pic out of the Old Air Catalog that shows the bolt holes for the head and intakes, and the differences between the intake mounting options.