Stock vortec heads can be drilled and tapped for standard intake manifold mounting.
Hippie is correct, there will be a port mis-match, but the mismatch is the proper type where the intake aperature on the manifold is shorter than then one on the cylinder head. Making the port aperature on the cylinder head wide enough and making the heighth on the intake taller will work well as long as the intake opening is not quite as wide as the head is and not quite as tall as the head is.
Vortec heads are excellent but they are lightweight and crackprone.
Racing Head Service now has the rights to the duplicate Vortec head and it is much heavier. (Over 8 lbs of extra iron per head), they are now my preferred choice to use and they come with screw in studs too.