anyone use the summit brand vortec heads? or is it better to just get the gmpp ones and have the machine work done. edit:i just got off the phone with summit, they said dart does the castings. anyone have flow#'s for a dart vortec head? edit2:just called dart, they only had flow#@.500 they were 232/138. i really need to do this before posting a thread next time, oh well, just a little more info for us all. gm vortec > summit/dart vortec

Exhaust flow is low. les than GM's 062 vortecs.

The GM 062 vortecs that summit sells with all the upgraded valvetrain and machining are a good deal.

These Summit/Dart branded Vortecs seem to be a suto-vortec design. Meaning they adapted their existing Torquer head ports to a vortec bolt pattern.
basicly your getting a dart torquer S/R head that has a vortec intake manifold bolt pattern.

Get a true "Vortec" design head either from GM or RHS. (both available from Summit)
There is more to these heads than just the flow numbers. Lots of hi tech swirl technology went into the GM design. Thats why these heads seem to out perform (in actual street performance), other heads with larger flow bench numbers and for less $$$'s.
The low/mid lift flow and swirl is hard to beat and copy.

Summit part # NAL-VORTECZZ5

exactly what i thought, i'm going to order the basic(cheap) gm vortecs because there is a guy in town that does pretty cheap machine work and i already have springs.