This is what I did. I have a 46 1/2 ton that I converted to tube shocks from knee action. I got some lower front tube type shock mounts off an Advance design series (47-50something.) that was in a junk yard. The mount was in a straight up and down orientation, I've seen some that have an angle towards the front of the truck I guess the choice is up to you. Anyway, got the lower shock mounts mounted to the leaf springs and measured the travel. Then I got on the monroe web site and found a shock with that travel with posts mounts on both ends ( choices are post or fork mount etc). These turned out to be off a 53 vette.

I made some upper mounts off of flat steel, bent them into a 90, welded some webbing for added strengh, attached to the frame and been running that way for about 5000 miles.

This is just a suggestion that worked for me I can't say it will work for you.