I love numbers crunching and hunting :) I may go try to find mine on my 2 beasts......

I found two sets on my 66 F350 and only one on the 64 F100.
Front framerail and under cab on 66 and only under the cab on the 64

Sucess!!!! Man that was easy....I found them both at fwd end of rail...If on RH side facing engine, they are to the rear of the battery tray if you draw an invisible line down to the frame...on the inner edge of the rail(closest to engine....hard stampings, easy to read.


Thx, cs65