I have been doing some digging and this is what I have found so far:
http://www.droppedaxles.com/index.htmlLists straight-axle lengths for older Chevy, Ford, & Dodge trucks. Very helpful if one was planning to run a straight-axle.
Of course, this may be the easiest way if you have the cash:
http://www.jimmeyerracing.com/1962-6..._Subframe.html And then:
Most solid front axels have a drop in the. The look is for a straight tube axel and that is something you'll have to buy new and usually you find a set of spindles and order the axel to fit them. The brakes are determined by the spindles and the more oddball the spindles the harder it's going to be to find decent brakes for them. Maybe you could take a front axel out of a 4x4 and remove the gears and axels and nake something that way. The Dana style axels are tube fastened to a cast center section and they usually have a long tube side and a short tube side. Maybe you could get a later model Chevy 4x4 front axel complete and find a junk housing that has a straight long tube side and use two long tubes and weld them together to make an axel. You'd be able to make it the width you want. Take the spindle and brake off the short side of the good complete set-up and install them backward on the extra long tube. If you use Chevy (or GMC) 1/2 ton stuff you can keep your 6 lug wheels. Maybe they didn't change the frames on the earlier Chevy truck ('55 - '59) so that you could fit the leaf spring set- up from an earlier frame to yours. Just ideas. GPster
So far this is what I have found.