sbc heads
I have 2 sets of OEM 305 stock heads, 1 set of those have been reworked and 1 set of aftermarket vortec heads for a 350. I was checking all 3 out for differences in combustion chambers, valves, ect. I noticed something that has me perplexed. The stock heads valve stems all have the same heights off the deck where as the reworked 305 heads and the aftermarket 350 heads have a different stem height between the intake and exhaust valves. I do know the stock heads have rotators on the exhaust valves and also they have spring cups on all the valves but the reworked heads and the 350 heads do not have either