Do these fenders require drilling or do they use factory bolt points?

These over-fenders leverage factory mounting locations, so you're working with existing holes on your vehicle. Verify alignment with your OEM fender before final fastening, and use the appropriate fastener type for your truck's attachment system.

What's the best way to prep these for paint?

Sand the surface thoroughly to remove any gloss, then fill any minor imperfections with appropriate filler if needed. Wipe down with a tack cloth before priming. Your paint supplier can recommend the right primer and topcoat system for FRP panels.

Will the 3.5" bulge clear my larger tires?

The bulge is designed to add clearance for lifted setups and wider tire packages. Confirm your specific wheel offset and tire diameter against the fender profile before installation to ensure adequate clearance at full suspension articulation.