I got this information for my '01 dodge ram 1500 by calling skyjacker and asking them. They offer a doubleflex kit with heim joints at each end that needs to be assembled/adjusted as part of the install. They even went so far as to fax me a copy of the install manual with the center-to-center distance listed. You might try checking their website for a .pdf version for your particular truck.
Cheers.