Hoisting a mill redux......

[AlanR]

Well, if you need to do it again after you've returned the pipe jacks you could use some 4 x 4 posts, they'll support ~7,500 pounds each.

 

[tigtorch]

You are, of course, correct. I was originally going to use 4x4's but I decided part of the safety factor in the way I set this up was the upwards force of the pipe jacks, it kept everything very firm and stable. Controlling the upward force with 4x4's is a bit more difficult, you have to wedge them in place and they have to end up being very nearly vertical.