The block must be bored to true the cylinders, usually the next oversize(030)?Decking the block
more than a few thousands is more of a racer thing.(See Kastner's book). On the 6, removing
excess metal on the cylinder is almost automatic to achieve a reasonable comp ratio. Once the block
has been bored the cylinder volume can be calculated. Then the combustion chamber can be cc'ed
and the correct amount of metal to be planed off figured. 9.5/1 is a good target.
Now you have to get NEW push rods to get the valve geometry back( to utilize your new 1.55 rockers)
that every Tr6 needs.(Good Parts)
Mad dog