We ordered these heads from Scoggin-Dickey fully assembled and with a maximum valve lift good for 0.545-inch. The cool thing about the Bow-Tie Vortec head is that that it features both center-bolt ...

Stock, in this case, means GM's iron Vortec small ... With 230-cfm max flow, these heads are actually pretty good, except when you notice that peak flow is at .700 inch valve lift, and no street ...

The Ferberts have been building engines and porting heads for years ... the valve now moves at maximum velocity to get to maximum lift. The piston is moving down the hole rapidly and by the ...

That may sound good, but the tradeoff is that the mid-lift flow numbers at 0.350 ... We did a dyno test of a set of iron Vortec heads without pocket porting compared to an aftermarket set ...