Originally Posted by cobalt327
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.
GM increased the length of all valves between the lock groove and tip starting when they went to self guided rockers, if you use valves for the older not-self-guided rocker heads there will be less distance between the lock groove and the tip there will be contact between the rocker and the retainer.
One of those damn little details to keep track of.