Thread: block numbers for sbc

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Ya i called a machine shop and the fella said that possibly a late 95 may have a vortec but the only way to really know for sure was to check the intake hole patterns when the intake was removed and look for a certain hole patterns. i was in a hurry and basicly was a little confused. Any ideas to what he was talkin bout concerning the difference of the heads on the motor. Moreless how to distinguish the two. Well if it helps any of you fellas he also mentioned something about something in the center and he wasnt talking about tappid pan bolts so i dont know.

The Vortec heads with the desirable flow numbers can easily be identified. ON ALL "good" Vortec heads, the intake manifold has EIGHT bolts. There are two bolts at each end of each head (four per head and eight per motor). These bolts are 5/16 dia and are VERTICAL (not slanted like the old small block chevy). Since there are no water transfer passages in Vortec heads, there are NO bolts in the center area of the manifold. And, by the way, ALL Vortec heads came with Vortec injection....there was never a carbureted Vortec head motor and never a tbi Vortec head motor.

The casting identifier at the end of the head is a saw tooth pattern on top of the rectangle.....it's easier to just look for the four intake bolts on each head however.

mike in tucson

Took a look at the bolt pattern and nope, not vortec. i really appreciate the tip now i know what i actually have and can finally start my mission for the 350 build. Thanks