Do I need a new gasket or clamp to connect this to my factory cat?

Yes — order a 2.5-inch exhaust gasket and V-band clamp separately if you don't have them on hand. The connection point at the cat uses a gasket seal, and having a fresh one ensures no leaks.

Will this bolt straight onto factory mounting points?

This system connects at the catalytic converter outlet. Test-fit the clamp position before final tightening to confirm clearance with your frame and fuel lines in your specific vehicle configuration.

Does the rolled tip need polishing or any prep out of the box?

The tip ships with a polished stainless finish ready to bolt on. If you want a mirror shine, light polishing compound works, but prep is not required for installation.