Rotating assy balance

Pressed pin pistons can break if you try and press them back out but they can be saved if he uses the proper support. If he balanced the crank, he balanced it to something as you cannot just balance the crank to itself, it needs up to 2050g of bobweight (total reciprocating and non reciprocating weight formula) to balance out. (example, 2050g is what Eagle builds into their cranks to give the balancer plenty of weight to work with and is not balanced to any piston rod assembly out of the box). Usually weight needs to be removed from crank on lighter aftermarket stuff as it is far cheaper to remove weight than to add tungsten at $75 a slug. Mismatched rod and cap is a guaranteed lock up after torquing them down, happened to me too on a very light stamped 3 and 8 cap. It was a toss up where it went and I rolled craps on that one. Swapped them and it was night and day when I went to rotate the lubed crank after retorquing them down.