Any of us that have dropped/installed an engine know what a PITA the front cross member bolts can be. This bad boy makes my day as I'm fabbing a lot lately and the engine goes in, then the engine comes out, etc.
Break the nut loose by hand. Crank it down on the bottom end of the bolt, clamp it and it hangs on all by itself. Hold it with your ankle and hit the top end of the bolt with a pneumatic ratchet (manual ratchets work too just slower).