If your lag bolts have stripped out, a possible fix is to cut four short lengths of angle iron, drill and tap one side of each for two machine screws that will hold each engine mount in place, drill the other side for two bolts or lag bolts to enter the engine bearing members from the side, then attach the pieces of angle iron to the engine bearing members. We looked at doing this on my boat. If memory serves, the forward pieces of angle iron could be thru bolted in place and the aft ones could be secured with lag screws. My old holes were good, and we just used slightly longer stainless lag screws.
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