Here is what the CCR says about ballast:

Unless superseded by class rules, all ballast shall be solid metal such as steel, lead, or uranium, and consist of
a minimum of five (5) pounds per piece. Each piece should be bolted in place with through-bolts, fender
washers, and a locking-nut / system (e.g. jam-nuts, Nylock, etc.). All bolts should be grade five (5). There
should be at least one 3/8” diameter, or larger bolt for every ten (10) pounds of weight (e.g. 20 pound block
uses two bolts). Nylock nuts or metal crimping lock nuts should not be reused.

I'm not sure if one 3/4" bolt equals five 3/8" bolts. Just an FYI in case they are strict for your annual.