The only low compression 340 pistons out there these days (like Silvolites) will still stick out the top of the deck by something like .137"...... still needs milling on the pistons. Now if you milled those by about .040" and use open chamber heads, and a .050" thick head gasket, then they would have decent head clearance. As noted, you'd have a really high compression 360..... works out to around 12:1 ! But if you then put in a big enough cam to run on pump fuel with this static CR, now the piston-valve clearance will become a big problem. So now more milling...... and at some point, you realize it is a solution that creates more problems than it solves.
