At some point in my 67 Coupe's previous life the owner put on a pair of Camaro quarters. I guess you all know I don't have the louvers behind the door any more. I was able to purchase a used pair on Ebay and now am going to get them welded in. Does any one know the measurement that the first louver would be behind the door jamb? Up and down is not an issue because of the body line.

Where the leading edge of the louvers start is 3" back of the door jamb. That is where the sheet metal dips inward. If that is not clear Colin I will photograph and annotate for you. Measure twice cut once

Mine is 3 3/8" from the edge of the door jamb to the beginning of the indentation, and 4 1/4" to the center of the holes for the first louver.

Thanks very much. Would have been easy if I had cut the replacements out myself but when you buy them it is a crap shoot.