There is a problem with the early 074 rods but the replacements should be ok, I take my engine apart and i put the piston in a drill press jig and with 2000 grit emery and light oil, I work the very top .020 ths down until I get a nice fit to the sleeve then I clean and oil every thing down mount and run it with 20% nitro 20% castro fuel with a prop, I lean it down right away so the engine gets hot and the sleeve expands reducing the load on the rod, run it cold( to rich ) and you will ruin the rod, because the fit of the piston will be to tight during break ln. I also use at least 5 head shims during all this, I havn't broken a rod yet