59 3100 Rear Frame Help

[pgnavy]

Hey folks, I need a photo of an original 58 or 59 rear frame, with the location of the rear bumper bracket holes. I am installing a bumper and brackets and not sure which holes to use. Unfortunately PO made this one look like swiss cheese!
When I use holes numbered 3 and 7, the bumper looks like the photos below (a bit too far from the bed body). The frame schematic from GM seems to indicate hole #1 and #5 might be the original location? When I install in 1/5, the bumper rests against the rear fenders. Help appreciated.

[mongocanfly]

that is a mess of holes....the pic you provided could very well be the way it came from the factory....remember they wernt as worried about gaps and spacing back then as much as functional.......I would plate over all those holes..get the bumper where you want it and drill new holes....it does appear 1&5 match the schematic

[_Ogre]

2nd picture appears correct

[Black_Sheep]

Originally Posted by _Ogre

2nd picture appears correct

I agree, use holes 3 & 7, I mocked mine up this weekend and it looks like your second pic. Obviously, having the bumper touching the fender is not correct. FWIW my frame has a bunch of extra holes too, I think the factory put them all there...

[_Ogre]

FWIW my frame has a bunch of extra holes too, I think the factory put them all there...

6 of those holes were used to rivet the panel truck extension onto the frame: 2 top, 2 bot and 2 side
that would be the 13.45'' extension piece in the pic

[pgnavy]

Thanks guys, I will keep it at the #3/7 location. Here are the measurements: using the #3 and #7 pictured holes.
Top of bumper to bed (looking down from top of bed) - 1 3/8"
Passenger side bumper to rear fender (sorry for the sideways photo) - 1"

Finishing up an entire new bed...wood, bedsides, tailgate, fenders, cross brackets, fasteners, fender welt ...bought Mar K parts. All good.

[Black_Sheep]

I had to go look at mine after seeing your pictures.Here’s a tape on mine...