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Hi guys. I picked up a set of used 799 heads that were supposedly milled .020. Just to double check I measured them and I'm getting some interesting numbers that hopefully someone here can shed some light on. I searched and found a few places (here included) that list stock height (valve cover to deck surface) for 799/243/317 heads as 4.750 (+/- .004-.005 iirc). I cleaned and measured some old 317 heads I have and got 4.757. A little higher than I expected but no big deal. Then I measured the 799 heads with .020 removed (supposedly) and these are the measurements I got at each end.
Head 1 side A - 4.752
Head 1 side B - 4.751
Head 2 side A - 4.749
Head 2 side B - 4.752
Looks like the guy lied about .020 being removed but the surface of the heads has definitely been machined, hopefully the pictures will show it. So if thats the case is it reasonable to assume that these numbers are correct? It just seems strange that the heads should be .750 but with definitly having something removed that they are all (but 2/A) over target height of .750
Manufacturer's tolerance could be the reason you are seeing that. Especially when these tolerances stack
Most likely would have to cc the chamber and compare to an uncut one to really know
From my research untouched 799's are around 64.5cc. I did the at home makeshift measurement device (plexiglass and syringe). All were right around 64cc but I would say my test method has a +/- 1 cc tolerance.
Maybe when I get some time I'll pull them back out and try to get more accurate results.
Deck to VC rail is 4.750”
My cyl head guy says this is the preferred measurement.
Just for grins, Deck to head bolt boss is 1.61”
Ron
Thats what I've always been told as well. The deck to head bolt avg is 1.609. Maybe my calipers are off when going out to the 4.750 range. They aren't big company like Starrett but my machinist buddy checked them out when I got them and said they were more than good enough for my application. Its been a few years since then however. Either way I'm thinking I'm just going to run a stock HG and live with whatever the CR is. Should be 10.9-11.2:1, 2 which for the weekend warrior truck its going in should be fine.
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799 head valve cover to deck surface height? 
