To do it right
you have 2 choices: Switch to hydraulic, or re-engineer the linkage, which would be my choice.
To do the linkage you'll need to make three pieces; the bellcrank and both attachment brackets. That's because you want to preserve the ratio built into the bellcrank, but have a greater distance vertically to cover, so it needs longer arms on both ends.
Then, to remain level, it will need to be raised by 1/2 the amount of body lift, which will require repositioning the pivot points on both ends. No hill for a climber.
Somebody might make a kit, but that's the kind of detail stuff that is commonly ignored by the folks who make body lifts. It's also the kind of detail that makes the difference between a good, reliable Jeep and one that's always causing Excedrin headaches.
If I knew a little more about you, like if you live somewhere close, I might offer to help you with it.
That's a hint, son.
Put some more info into your profile.