In preparation to trying one in my uni, I started taking measurements. As stated, that quickly became confusing!
I just discovered I no longer have any 61-63 non-uni F100 cabs. Ah, but wait, I have the mixed-vintage F350 tow truck, which is definitely a 62 rolling chassis, with 63 trim and 66 grille and upper valance
It is a "flat-roof" cab with the big truck floor and steps. This led me to believe that, with the exception of the floor panels, the cab panel dimensions would be the same as the early non-uni slicks.
I started out measuring windshield headers, and found that the dimensions were all similar.
I then measured seam to rear window rubber on the trucks without a headliner in the way and found a difference of ~ 3/4" between the uni and my sun-roofed '66. Ok, let's check a couple of the other "high-roofs" ! The '64s, the stock '66, AND the big-window conversion ALL appear to have the same center brace, although the BBW has a spacer in the dome lamp area.
Not getting any concrete evidence here, I decided to measure the outer dimension from cab horizontal seam to rubber window moulding. The unis differ from the "high-cabs" by -3/4".
Well, let's check the "low-roof" tow truck! The seam to rear rubber dimension is the same as the "high-roofs", maybe even an 1/8 more! You may say, "well the rubber surround may differ". This is certainly true, in reality I'm measuring to the "crease" where the rubber fits.
So, are these findings standard on the bigger trucks, and if so, does that affect headliner fit on the F250's/350's, etc.? It is entirely possible this is the result of 50 years of potentially mis-matched parts. I'm just curious if anyone else has noticed this.
I'm still inclined to think the 'glas headliners will fit the earlier trucks.
Bronco Tom has kindly offered a test-fit prior to his installation, so we should be getting back with concrete information in the future. I do know that suppliers offer differing headliners for the earlier trucks; I just haven't found anything to indicate the custom headliner will not interchange.
Thanks in advance for any experiences or comments!
Paul

