Anyone know the size needed for Helical kit to repair stripped primary oil bolt on an 07 Road King ?

 

Are you referring to the bolts that secure the cover or the drain plug? The primary bolt size is 1/4-20 . So you need a 1/4-20 helicoil. The depth may vary though, i think i put about 1/2" deep in one of mine. Not sure about the drain plug...

 

Drain Plug