Reading one of Dave Vizards books on race engines,- Metal can be suprisingly elastic, monster torques on head fastenings can cause the bores to distort, discuss.
Also on some engines which pump coolant into the head first from the pump, the small head gasket coolant holes are there for a reason, to up the pressure in the head to raise the boiling point of the coolant there and prevent steam pockets at local hot spots. This doesn't apply here as coolant is pumped into the block first before transiting the head gasket into the head, then out to the radiator. But raising the coolant pressure in the block would make cavitation erosion less likely, discuss.
If you need a smooth sealing surface, the following method has done me fine.
1, Clean all the gasket crap and grot.
2, spray WD40 onto block surface, fairly thinly,
3, lay on head,
4, yank head,
5, look at resulting pattern,
6, where the oil is disturbed, the two components are touching,
7, with a really good flat VERY FINE oilstone work those areas of the head LIGHTLY,
8, wipe clean, spray another fine coat of oil,
9, repeat a dozen times or so until the entire surface oil is disturbed when the head is placed on the block.
10, who knows which is "flat", but the crush on the head gasket is now dead even, and will seal a treat. Methalated Spirits to remove the oil before you apply the gasket.
11, If your head was REALLY warped, congratulations, you now have a perfect seal, pity the camshaft will now probably seize and snap the cambelt. :twisted: There are limits.
The usual warnings apply, I am let out of the institution every other weekend, only a complete fool will try this, but it works for me. :wink: