I gotta tell you my experience with those DIY4X mounts.
When I was mocking up my cradle for the doubler, the engine was bolted to the mounts, and the rest of the drivetrain was supported temporarily by a jack and milkcrate w plywood on top of it. Not a good idea as the jack rolled out of position and the doubler dropped several inches and it was all supported by those two engine mounts. I was amazed it didn’t break the block with all that weight hanging back there. The mounts held everything and suffer no damage.