The long travel comes from the pivot. They could cycle whatever the shocks allow with that set-up. Articulation would not improve too much though. The only thing weak about them is the factory post style mounting, because the lower pivot puts some serious load on them and would try to twist them out under hard braking.They don't even appear extended for the 'long travel' that the seller boasts.
You're not confusing the 429CJ (Cobra Jet) with XJ (Cherokee) are you?They built them to put Ford front axle in a Jeep Cherokee and would make them longer than stock. That is what it looks like to me.