Alsfarms; first off, why would you want to raise compression. The original engineers did extensive development before the cars were ever put on the road. second, I have seen more than one brass era Buick engine blow the cylinders right off of the block from doing this same thing. and they are not Tee head engines. I have a customer that did exactly what you are asking about on a 1912 Pullman and he blew the jugs off of it from only adding 1/4 inch to the top of the pistons on a 4.5 inch bore. Don't do it please. you will not see a difference in performance, and if you do add compression and it blows, you will have a very expensive repair bill.