Every 67-8 has this shrinkage problem except maybe the late 68 standard that used the Mustang low profile moulding. Here is my fix. I remove it, place a paint stir stick in the U channel on the front, place it in the vise and use a couple of blocks of wood on the other end with a C clamp. Then I get a ratchet strap and get it tight. Next I turn my heat gun to about 850 degrees and run it up and down the length of the moulding and every minute or so I click my ratchet strap another notch. I got this one to stretch 4"! The problem is it shrinks unevenly and when you stretch it it stretches unevenly which puts the 2 screw holes in new locations. Somebody with more finesse than I could probably get the screw holes to line up. One other step is you cannot easily on a cold day like this get it reinstalled before it cools. Once installed you need to smooth out the puckers with the heat gun.
The passenger side was still tucked in but pulled away from the roof. I stretched this one to 70" which I think if you went 69" and it started to shrink again you would have the same problem. I got the screws to line up on this side by focusing the heat on the areas that shrunk the most, not the entire length.
If you look close you will see a line where the moulding used to ride against the panel. Now it rides about an inch higher and that is OK. The heat gun took most of the crease out.
I wouldn’t have thought about heating these while stretching. Mine surprisingly where not that bad, I was able to find the original screw holes even.
thanks for the tip Don. We will give this a try, as I have several that need stretching!
Very impressive, Don! I would never have thought to do that.
I wonder if this would work on my vinyl checkbook; my budget needs some serious stretching. Whaddya think? Good idea?