The conrod/big-end/piston are all junk from the factory anyway.
Do a competent rebuild with a steel conrod with Alpha roller big-end, a Hitchcock 8.5:1 piston in a new alloy barrel(not the cast iron stocker) properly bored/honed to .0055" clearance, retard the stock intake cam only by one tooth counterclockwise(leave exhaust cam in factory position).
The other parts should be okay to use.
That is the recipe.