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Old 12-31-2012, 11:47 PM
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Originally Posted by cobalt327 View Post
Do the valves w/the 0.250" tips have the 30 degree backcut like used on the Vortec valves? If not, it will likely be cheaper- and might run a tic better- by using Vortec valves to replace the non Vortec valves.
Just did a quick measurement on my assembled c/n 062, L31 Vortec heads (has stock Vortec valves) and found the split lock-to-valve tip measurement to be the same as on an assembled pre-Vortec 2-groove valve head (c/n 441). In other words, the Vortec valves I have do not have a longer tip than a standard SBC valve. I do not know if that was something GM changed during the production run of Vortec heads, or if this is normal for ALL L31 Vortec heads.

The Manley stock installed height 1.94" intake valves all have .250" (standard) length tips except for one 0.290" valve (p/n 11860-8) in the Race Master series.

Manley stock installed height 1.50" exhaust valves all have .250" (standard) length tips except for one 0.290" valve (p/n 10077-8) in the Budget Replacement series.
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