88 Motor mounts

How do I get these mounts out. I put the impact gun on them and they just spin, but the crossmember is closed in, so how do I get in there to hold the nut that is obvisously on the back side????

There should be a hole some place on the bottom of crossmember where you can get a hand and wrench in there or a long extension with a socket or wobble socket.
Good luck
MT

That's what I was afraid of. Putting a 4.3 in this in place of my 283, so gotta change `em. Thanks for the advise.

Good luck and let us know how it goes.
MT