Rotissiere modification questions

[CamarosRus]

I built my rotissiere with stationary vertical end posts.

Camaro body will turn with one hand.

I'm wanting to rework end posts so they can be raised/lowered for ease of installing body

Want to save rotating section complete so trying to figure easiest way to telescope what I have. Vertical Post is 3.5"x.120 wall so 3" sq is too loose inside. I could replace vertical with 3.5"x.180 so 3" could telescope.
Then weld small portion of existing 3.5" that has rotating assy onto the 3" telescoping portion (confused yet?)

ALSO.........would like to SEE pics of those using used bumper jacks to raise lower, versus more costly hydraulic jacks.

Thanks for your input