When I did mine, I traced the trim piece with a grease pencil once I got it where I wanted it, measured in the thickness of the trim piece, then held the clip to that line. Marked the holes and drilled. They came out real nice. Don't know if that helps any.


http://s971.photobucket.com/albums/ae197/jon63c10
1963 c-10 shortbed stepside 427 BBC T16 HD 3 speed
1963 c-10 shortbed fleetside 348 "w" 1st gen big block & powerglide