Cowl induction hood- grille opening bolt size??

[DWC]

I have an Auto Metal Direct 2" cowl hood for my 68 Camaro. I have the Undercover Innovation cowl grille, which came with 10-24 bolts to attach the grille. Their directions state to tap the holes before installation. When I tried to tap the holes with a 10-24 tap, it started to thread with light force, then the riv-nut started to spin. I tried the tap on another riv-nut, same result. I've tried both metric and standard taps of various sizes, but none seem to match the riv-nuts thread pitch.

Does anyone know the correct thread size for these bolts? (I called Auto Metal Direct, and they didn't know...) The hood is recently painted and the size may be 10-24, but I want to be sure before I apply more force to the tap.



Thanks,

Daniel

[TheJDMan]

10-24 possibly?

[DWC]

Steve,

I actually typed the wrong bolt and tap size in my original post (it's corrected now). The grille came with 10-24 and I tried a 10-24 tap. The riv-nut threads don't look fine enough to be 10-32.

I'll try emailing Undercover Innovations and see if I can get an answer.

Thanks,

Daniel

[DWC]

I received a response from Undercover Innovation and they state the factory size is 10-24. So, I'll try to tighten the existing riv-nuts, or replace them.

Daniel