To move the head 1/8" would be fairly easy, farther than that lots of things will come into play.
The first 1/8" would involve simple elongating of:
Head bolt holes
push rod holes
Some allining of water and oil drain backs and the dowel pins.
To go farther than a 1/4" will get the cylinder close to the head water passage between pushrods. And the bolt boss in the siamesed port will get thin and close to water.
It may be way easier to just relieve the block. I do have a bad 250 that can be cut up. That way thickness's can be checked at top of cylinders for relieving.
Armond, Nice pic! Good showing of a bad chamber design to go over the block. Tom
