Reply by Granddaddy1

If I understand correctly, you basically have a sheet of 3/4” plywood installed on 4×4 joists placed 24” on center. Then the 4×4 joists are bearing on concrete footers or blocks placed 24” on center. If that is the correct assembly, and your concrete footers are level and adequately placed, your floor system will hold much more than what you’re considering.

Good luck!

-- Ron Wilson - maker of fine firewood!