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Rod bearings can be removed and replaced with the engine in place for sure. Once the oil pan is off then the rod bearing caps can be removed and the bearings replaced.
Since the main caps are crossbolted, which means there are bolts running into the main caps from the sides of the block, this will make main bearing replacement with the engine in a little tougher. You may have to remove other components to get some of these bolts out if you need to replace the mains too. It's going to be tough to get the upper main bearings out and the new ones in with the crank in place. To make this easier you might remove all the main caps and try to let the crank sag down some and open up a little clearance between it and the upper shells.