Just recently installed these on my '59.
The end with 2 bolts go thru rad support, middle bolt goes to grill panel and inner side of bumper filler, outer hole is for front of bumper filler. You will be able to see the last bolt by looking at the front of truck in the front edge of bumper filler.
Here's a pic from under the bumper looking back.
Darren
[IMG]http://i171.photobucket.com/albums/u320/durwoods78/1959%20Chevy%20Apache%203600/SAM_0367.jpg[/IMG]