I did the same thing on the inside of the frame on my dads truck. 
Fairly easy solution and seems to hold up well. I've put several on and off road miles on it and no problems yet.
I will move it with u-bolts for the set up and testing. Thanks for the info. I will then build a stronger unit that does not hang down so much and lifts the trans.
How are you coming along??? I would like to see some pics of what you end up when you get done.
