i would think you could. But to get to your upper main, you'd have to drop the crank. To get access to the rod bearing, you'd be better off to drop the crank and push the piston down. In order to drop the crank, there are a host of things that need to be done, removing all the rod bearings, main bearings, transmission/flexplate or flywheel, timing chain cover, timing chain therefore radiator and shroud-----Heck just pull the engine.