Screwing on bolt style holds?

I got a few holds for free from my local gym and want to screw them onto the side of my crack machine (T-nuts wouldn't really work on it). Is there any good way to screw on a bolt style hold? Big screw in the bolt hole? drilling new holes? any ideas?

Why wont a t-nut work?

Just spit balling, but you you could probably use an appropriately sized lag screw.

Just buy a countersink bit and drill 2-3 holes in each hold and attach with screws.

People screw on T-bolt holds all the time. Alot of times it is just to stop spinning they will put a few screws on the edges but you can attach them with just screws. It depends on the type of material the hold is made out of but I would pre-drill them or you risk breaking some of the holds.