Would a 70's bed sheet be the same as a 66.

[Jcreezy66]

Obviously not the outside of the boxes are going to be the same, but I was wondering if I could cut out the inside bed floor and put it in my 66? Any help will do. Thanks!

[Ranchero50]

Possibly but not probably. Frame mount points should be close. Inside dimensions too. I'd sketch a drawing of your bed to go shopping with. Figure out what you really need to replace and where you'd cut / weld it together to see what you need for repair panels.

[66f250cs]

I took only a few measurements from my 66 & 69 and long beds. The 66 is loaded full of crap since I am moving to a new house TOMORROW. Yea. With a 36 x 60 shop 11 foot ceiling drywalled and lighted. As you can tell I'm jazzed. The 66 & 69; center to center on first screw directly behind bulkhead across frame is 31 3/4. Center of those screws to bulkhead is 2 plus/minus 1/8. The 69, next sets of screws towards tailgate is 31 1/2 across frame. I did not check the 66 but I think they're going to match the 69 not only across the frame but front to rear, too.
But note; the box is much closer to the cab on the 66 at 5/8" vs the 1 3/8 for the 69. Hope this helps.