Rear End Conversion - Confused!

[ssiegel4]

Please forgive me as I try to explain my situation; it may sound confusing at first.

I went ahead and made the changes to the rear end of my '73 vert as described in the first screenshot below. The rear quarter panel extensions on the '71-72 are supposed to be longer than the ones of the '73 so that they meet the top line of the curve where the bumper fits in. In the second pic is the original '73 quarter panel extension from my car. The third pic is an extension from a '71, which is indeed longer in terms of that thing jutting out of the bottom (still not sure of the purpose of that thing, much less the function of the screw hole); however, the top portion is the same length as the '73, which means that it's still too short to meet the top of the curve (see 4th pic), note the space where the extension doesn't meet the curve).

Can someone please explain to me what I'm missing here? I must have misunderstand something. Thank you all!

 

[Doug's 73 Mach1]

73s used plastic filler pieces, see photo. The 73 quarter panels had space for these.

 

[rvrtrash]

If you end up needing the extensions, I have a left side 71/72 coupe/convertible extension in great shape. $20 plus shipping. You'll need to paint it.

 

[Hemikiller]

My gut says that the quarters or lower quarter patches were installed too low. Common error, especially for a DIY restorer. Pic below is of my 71 Mach. The driver's quarter is original down to below the lower body line. You can see where the bumper pocket is supposed to sit in relation to the taillight opening.