ok here is somewhat of a dumb qustion. 2 out of my 3 pistons have a hair line crack.it is a looper 60 hp the crack is on the oppisite side of the exhaust port hole.witch i belive it would be the intake hole on the piston were the crack can be seen. are they junk. i was just going to change the upper crank bearing do to a slight chatter up near the flywheel.looks like i will need to go a bit deeper in my pocket if the pistons are unuseable. at this point i am going to mike the cylinders and see what i get for specks.if i am within specks should i just hone out the holes. and new rings or should i bore and go all the way. the new piston kit are not looper pistons. so it may run a little better with lower comp pistons do to todays gas vs the gas in 1970 . ive been told there is a converstion kit for the wrist pin bearing something about 5/8 vs 3/4. any one no about this. is the new pistons wrist pin smaler or biger. what was going to be a 200 dollar fix looks like i should add a few zeros