Rotisserie Build. Will it hold together?

Got my bases done, built one upright. Made where the base and upright will separate. After uprights is rotator heads. Going to put 6 pneumatic casters on it, each rated at 350#. So I can go offroading and drag my rotisserie.

So, the pipe is oil well casing 3/16 wall. The angle iron is 3/16. The gussets are 3/16. The square tubing upright is 3/16 wall. The flat pads for casters are 3/16.

The upright is attached to the base with 7/16 grade 8 bolts (6 per upright) the base is tapped for the bolts.

My main concern, is the attachment by bolts threads, i believe.
They grab 3 threads each, in the pipe.

Its for my Duster.

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