Center Cap Bolt Length

[rudey737]

I had two 15x7 truck rally wheels powder coated silver and had new tires mounted to them for the front of my truck. They look great, but I haven't added the trim rings to keep from scratching them up.

I also haven't added the center caps yet. I tried yesterday and today, but it seems the caps are too thick for the bolts that worked with them previously. They used to fit on my 15x8 wheels fine. I thought the holes in these wheels were too big for bolts, but the bolts fit fine when the center cap isn't there. Does anyone know what the length of these bolts should be?

Has anyone else had a similar issue?