Rob,

This is off my 70 Challenger R/T built in Hamtramck. It's a V code CA car so no exhaust tips.

Don't know if it's correct as I have seen the super long screws too.

The threaded length was 3/8" and with the self tapping notch.

I'll check my collection of 70 valence brackets to see if any of those have the long screw.

Chris