so, is it as easy to swap the newer front end components onto a 55-59 truck? Or by "62 and earlier" do you mean 60-62?
60-66 are relatively easy to upgrade with the later front ends.
with the 60-62 you have a few more holes to modify is the difference between years and with the torsion bars gone it does free up more room.
59 and under are a different operation and you may find more relivant answers in forums of where there is more people doing those conversions
ron