I think I will go 64" leafspring. Been doing some research and some of the leafsprings and capabilitys are pretty awesome and simpler than a link setup. Also ride is a big factor I like the old iron but want nice ride. Been doing zf tranny conversion with 400 ford and its going well also. Was checking into giant motorsports and their offroad raceing trucks and their leaf setup was awesome. So to do this conversion I will have to add some length to my frame for this application. if you look at www.offroaddesign.com crewcab truck you will see where I'm going with this truck. 1970 crewcab 4wd with custom bed and 64" leaf spring rear. The factory springs are around 51" and ride is not good. Need to upgade to a modern leaf but fab work is required. but nothing rocket science for a guy with a welder and torch and decent skills. Catch you later and its snowing today in sheridan wyoming.
You can find 64's in the back on any 4x4 IFS 1/2 ton chevy. That is a popular upgrade for the square body guys to obtain more droop. I have seen a few on the forums that run them in the front also. Most run a 52 or a 56 in the front.
Just found out the 2008 and newer fords have the 66" spring. I will be running this spring from a F-250 for my application. the spring is 33 1/4, 33 1/4 on the center. factory is around 25 This is needed for my application. Will be using some offroad design spring hangers also for my application. need a spring that rides nice and capable of doing some hauling also. Not a total off roader, will be huntin/work rig. Will get some pictures once I figure out how to get on here but not computor wiz yet.
will be running a air bag eventually up front with some form of link suspension. Want and old school look with a modern suspension underneath will be a nice ride. I have some coil springs as of now and will use those for now. they are the Jeffs bronco graveyard flex/articulation springs and really ride nice. but the air bags are awesome especially when dropping off a curb on a street or similar normal street or county road situations. Having to do part of this installation outside and it snowed last night a couple of inches. catch you later and getting up to speed on some of the newer stuff that is possible and upgrades to our old iron.
i now have a 1970 ford 4wd with a 4 link upfront all custom. went with a deaver coilspring up front. Rear now has a 66" leaf out of a 3/4ton ford from a 2009 i think. its all installed and lookin good. Just got rear disc setup done also. rear disc i used ford fronts calipers and modified to work on rear. lots of brake on this old truck. will have some picture by this weekend. all mods are ford parts and no chevy cross over stuff. just like keeping it all ford.