my 69 has bolts instead of u-bolts holding the rear in, is this ok

Yes that is ok. I just stripped a posi diff from a mono car and it did not have u-bolts. Not sure if all were this way but I think so. The multi leaf only had u-bolts on one side of the shock plates and the other side of the plate has studs as well.

bolts only on a mono leaf rear were stock, but with any type of torque, you will rip the bracket off the rear. Use one u-bolt (per side) to be safe!

Stock mono's had "T" bolts. I prefer "U" bolts when I reassemble.