does anyone know how much you can plane a A14 head when on a A12 block couse the last thing i want is to get a valve exchanging its thoughts with a pistion AAAAAAAAAAHHHHHHHHHHHHHHHHHH now that would be a problem

it all depends how much cam lift you have, as well as valve duration. Most of the motors i have assembled, i have had to put fly cuts in the piston tops.

With a mild overstock cam, I have cut close to .250 inch off the head to fit on a dirt track motor. It made the rockers fit at a weird angle but it run like a bat out of hell. In that class, if anyone wants to buy your motor for $400, you have to sell it or not run for the rest of the season. It is much cheaper to up the compression that way than with pistons. I have had an A14 with up to 11.5:1 compression ratio using this unorthodox method but it won a bunch of races racing against all types of 4 cylinder motors. This class of cars have to weigh 1 pound per CC if it is over 1500 CCs but under 1500CCs has no weight restrictions.

Place a wad of putty on top of a piston,
install a used gasket and the head ,
adjust the valves,
rotate the crank two turns,
remove the head,
cut the putty at the valve indentations,
measure the thickness of the putty
and that will tell you exactly how much you can take off of the head.

After you shave the head, do a compression check so you can adjust to the octane that you need to use.

Mareo