What is the load/tension/pound rating for the HD bars? What about stock? How much stiffer are they?
Stolen from NICO / Rev_D21:
About Aftermarket Torsion Bars:
Nismo 2 stage torsion bars are made by Sway A Way (SAW). The SAW part number for these bars is 1440. These bars have a second set of splines towards the middle of the bar itself. A lever is attached to the bar that limits the twist of the bar. Once the bar reaches a set amount of twist these levers press against the truck thus shortening the effective length of the bar which increases spring rate. You will notice that SAW # 1440 is not available in the SAW catalog. 1440 is only available through Nismo. Also note that it is the only bar to feature the lever mechanism that I described above. These bars are the actual bars that the ITT trucks used, so if you are trying to build an actual ITT based Hardbody, you will need these bars.
I took a chance on a set of SAW 1446 bars. Want to know a secret? SAW makes the bars that are sold on 4x4parts.com and for Calmini. The only differences are the color paint they used to powdercoat them. If you look at all the part numbers they all end in 1446. SAW 1446 is a one-stage torsion that lacks the second set of splines for a lever mechanism but has a spring rate that is 30% higher than stock. SAW bars are powdercoated red and are the less expensive way to go. Why pay other companies markup when you don't have to? The Bad: SAW 1446 is not what most ITT Hardbodies ran. If you are trying to build an actual ITT Hardbody you can use these but just know they lack the second stage action that the Nismos provide.