I noticed that all my intake valves have approx .020 less installed height from the factory. I just measured the valves and the intakes are slightly shorter. Is this done to offset the heavier valves? Not sure if I should even out all the heights or maintain what GM did.

Vince what casting number head we talking about

Mike this is a 454HO head:

12562934...00-up...rect...OPEN...Gen.VI 502 Marine

Anybody else?

Less as compared to what - the exhaust valves?

Yes Joe - glad you caught that! Actually you knew about the difference is heights didn't you?

The intake valves have less installed height than the exhaust. This could be b/c the intake valves are slightly shorter. But it does seem like a good idea to preload the intake valve a little more b/c the intake valve is so much larger.

Sorry it took me so long to get back. I have seen this before on the bbc heads intake shorter. It won,t hurt anything unless you up aginst tight valve lift. Even alot of after market heads are this way some as much as .030.

Vince, keep in mind, you have .030 less lift on the intake with your cam. You can run these with less installed ht and increase the overall pressure slightly as compared to the exhaust side. Your cam will automatically induce an extra 13# open pressure with your double springs (441# rate) if both were set at the same installed ht.

So would you suggest evening out all the heights or just maintain what GM did?