Going to add a hitch to my '99. Looking at the install video it appears that the nut plates that exist on the right frame rail are retained and used (left side has no nut plate).

One of the 4 threaded bolt holes to be used also received a bolt for the rear tail pipe hanger.

In the video it look.s like these are all 12 mm holes. Looking at a comment a person claism that some on the plate are 12 mm and others are english threads.

Confusion. Anyone know what threads exist in the last 4 holes of the right frame rail nutplate? Are these all 12 mm or are some english on a given plate?

Mine are rather rusty and I want to run a tap up through them, but don't want to screw up any threads if there is actually a mix of threads on this plate.

Any feedback here greatly appreciated.

Larry S