we leaned a buddies quad out once and blew it the first time out. i would go with what your engine builder recommended.
edit: 6 months of hard riding can wear stuff out. maybe it was a bad rod from the factory. There is no 100% true answer. Motors blow, sometimes sooner then later, that is why we have tools. lol. There is a guy with a superjet motor that had a rod let loose and it cracked the bottom and top case, cylinder, intake manifold, carb base, exhaust manifold and the head. Motor was complete junk, nothing worth saving. now that sux!