Do these heads take the conventional intake bolt pattern or the new style bolt pattern?

I think they have versions that use each kind.

I have read a couple articles in chevy high performance on them that indicated that they have a small version that uses the vortec pattern and a larger port version that uses the older pattern. They both are supposed to have a "vortec style" chamber, but one has around 170cc intake port / 1.9" valve while the other has a 180cc intake / 2.02" valves.

You might try to email them. I have not seen any flow numbers on them comparing them to actual vortecs, so I have no idea how good a copy they are.

Thanks Charles!

Their "906" is a thick deck copy of the Vortec. Looks like to me that the short turns are a bit more rounded, so in theory, it should perform better than the original Vortec. The 906's use only a Vortec bolt pattern. HTH

The Torker head is the one that will fit standard intakes.

The intake runners are 167cc's.I have bean told that it is the same port as in their Vortec replacement head.

The Torker head is available with 194/150 or 202/160 valves.

The combustion chamber has a D shape to it,available with 67 or 76cc chambers.
A GM and Pro Topline Vortec head has a heart shaped chamber.
Also the Pro Topline Vortec head will only accept Vortec style intake manifolds.