Bolt hole locating 3 Arm mirrors

[Hipburwig]

So have a 91 R3500 drw but it has the concealed three bolt mirrors which are pretty much useless when towing. So I bought mirrors off a 86 C3500. I have a general idea of where the holes should go for the mirror arms but they just don't quite look right and i think one of the arms is a little bent. Has anyone ever measured The bolt Hole locations or is there a diagram somewhere from a build book or something that will tell me where to drill the holes? The only thing I've been able to find is a diagram for the sport mirrors for the early squares.

 

[bucket]

Iirc, @Old77 's truck had the large tripod mirrors and the bolt holes are still there. Maybe he can get some measurements. Or maybe I'm remembering his old Suburban...

If you got the smaller tripod mirrors, I can go measure my '79.

 

[Old77]

yep. the holes are still there on the dually so I can measure for you. I'll try and get those measurements for you today.

 

[Hipburwig]

That would great.i have been looking for ever. I even carry a tape incase i see one in a parking lot our something.