can we please talk width and length ?????????????????
I think, if this is the numbers block, it should stay 340. Trying to do too much will increase the odds of problems and adding oddball stroke combos will cost a lot more in the end to get running. So for me, stick a small solid lifter cam in it, build it for 9.5:1 compression, and go have fun. You should have no trouble making an honest 320-350hp with modern machining, good assembly, and good "off the shelf" parts. And it won't wear itself out or cost mountains.