[X-TECH MAN]

I can answer on the icing down the heads. IF you chamber and runner volumes are close and I mean very close then by icing down the head it will bring the temp. down quickly to ambiant temp. This will keep the alcohol (or whatever they are using) the tech crew uses to CC the chambers from expanding and therfore the chamber would not hold enouugh to be legal. The opposite is true when CCing the runners. The expansion would work in your favor but again it depends on how close you build the heads to NHRA specs Some guys build very close and remember all burettes may not be exactly the same. Allow a little extra room. .2 to .4 CCs will not make the car run any faster. Some I have checked in the past have been DEAD ON if you hold your mouth right.....lol. If they are not close then dont worry about it. Do not remove the spark plug (like some try to get away with) and stack washers under the plug to gain CCs if you type of plug uses a washer. The spark plug should be sealed with paint to the head anyway and the tech inspector will look for it. Doing so could get you DQed.
The tech crew should have thier own checking lifters. See what the other DP racers are doing. You should carry a valve spring compressor to remove the valves requested.
Someone else will have to answer the rest. Ive been out of it for about 10 years or so. Good luck.