Thans for the kind words Abe.
The blue shocks are gas filled units I got when I converted my Mustang II to Air ride suspension.(I can't even remember what make though) I'll have a look later...
I do think they would be too long in a stock installation and as you can see they're located in a totally different place from stock.
I'd be very suprised if yours haven't been replaced at some time in your trucks long life.

If you have an old shock you'll need to measure the open and closed lengths and try to find an equivalent unit.
Obviously the bolt diameter/bush mounts are critical too.

Personally I would opt for gas units (if you can get them) as they offer better overall control and better handling.
If I find out any more info,i'll let you know.

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.