Lincoln said:
I'm confused by the length of the upper arms and the seperation at the frame end. I've read that it doesn't matter as long as their not too short to they should be close to the same length. And I've seen setups with hardly any verticle seperation at the fram to more than 1/2 the distance the axle has. 
I though about making the lower arms longer and moving the axle mount up, but I don't think the center link (brackets, frame, and axle) can handle the extra stress. If I'm going to have to mess with those I might as well build new.
Complaints:
1. The lower arm mounts hang low and to the sides of the frame. Some stuff I couldn't even take a strap over because I was worried about tearing them off. When they hang it's stuck.
2. Tacky hills cause the left front to lift while going up. The air bags helped with a lot of it. On some of the climbs in Moab it would still lift the left front about 6". I've even got it to lift on tacky dirt.
Those are the two biggest complaints. I've gotten used to the rear steer and other things.
I decided I need to get the winch on soon (snow runs already starting) so I've taken part of my bender money for a bumper fund. For now the plan is, bumper, gears, cage, rear suspension. Hopefully the rear suspension will start in Feb. Not making the bumper is just to save time, I don't want to have to park and ride this year.
The vertical seperation between the upper and lower arms mounts on the frame end have an impact on the IC location, and the stress on the mounts. More separation moves the IC forward, and applies less stress on any one mount. Less separation shortens the IC length (and the relative height then becomes the determinant factor on the anti-squat result, much like with a leaf or radius arm system).
The upper and lower arm length differences impact the pinion angle gain as the travel is cycled, and it works with the relative arm angles (each is important). Right now the wildly different relative angles of the two arms is the determinant factor. Correct the determinant factor, as close as possible, before changing arm lengths.
Try to relocate the axle end of the lower arm higher, to make the arms more parallel. This will increase the IC length, move it forward, and lower the forward end of the roll axis, while reducing the anti-squat.
For kicks, lower the frame end of the upper arm (make it less parallel), as a method to lower the AS, to see what happens to the IC, and the pinion angle? Lengthen the lowers and test it out (on the shop floor). Playing with the options will model the results of changes (and show why one change is preferred over another).
The front end lift on hills is partly due to the short IC and it's location behind the front axle, or nearly under the CG. The IC location is the determinent factor contributing to the front end lift. Relocating the IC, forward or rearward in relation to the CG, will change the leverage the suspension has on the chassis.
Move the IC to the rear of the CG and the AS takes over (rear lift, and hop).
Move the IC forward, far ahead of the CG, and you reduce it's ability to lift the front end. You need to place the location where the chassis weight works on the axle way out on a long lever arm (but not too far). Raising the axle end of the lower mounts will relocate the IC forward. I would not raise the axle end mounts higher than needed to keep the IC behind the front bumper.
IMO, the IC needs to be between the front axle and the front bumper for a vehicle that has the engine straddling the front axle (further back for a front-mid-engine where the dampner is behind the axle centerline, like in the textbook racers). With rockcrawling and wheeling there is no testing data to offer ideas on where is the best place to locate the IC (not like with road racers or drag racers).
The end result will still have some angle to the lower arms (they will not be parallel to the ground). This angle may allow you to tuck them up into the frame rails, or inside the frame rails. If you want to reduce the rear steer effect, you need to narrow the frame end mounts of the lower arms. This will pull-in the forward point of the roll axis, making it less sensitive to changes in the suspension travel (right now the roll axis becomes increasingly steep as the suspension extends or jacks).
Add the pinion to the drawing. Draw a line between the arms axle mounts and add a line for the pinion angle off of this line (two lines representing the pinion and it's restraints in the axle mounts, side view.) With a SYE and DCCV joint shaft you want to try to keep the pinion pointed at the tcase.
Cycle the suspension and watch the pinion angle change. I find it easier to draw this on the shop floor, full size, and cut cardboard to model the axle mounts and pinion. I then draw the arms, and axle, at full compression and extension.
With a level upper arm (looking at the drawing) and a steep lower arm the pinion nose will roll down as the system compresses, the opposite of what you want for u-joint life (OK with limited compression). The pinion angle on extension is the beneficial direction, and you want to keep this attribute. The arms need to be closer to parallel, but not true parallel, even if this reduces the beneficial pinion angle gain on extension (it can be fixed by changing the length the lower arm).
With the arms more parallel, and the IC lowered, you can alter the pinion angle gain by changing the lengths of the arms. Longer upper arms, more equal length compared to the lowers, and you reduce the angle gain change. Shorter lowers do the same (something you will likely need to do to raise the axle end mounts). Moving the axle mounts forward or backward, as the arms length changes with fixed frame ends, will locate the pinion in the middle or end of where the angle gain becomes a problem.
Summary?
Raise the axle mounts on the lower arms (to lower the AS and IC).
Raise the frame end of the lower arm mounts to the extent allowable, without moving the IC too far rearward (you do not want parallel arms, nor do you want arms that locate the IC far behind the front axle centerline, not behind the CG like a lifted leaf sprung XJ).
Narrow the frame end of the lower arms(to reduce the roll axis rake change through the travel range).
Change the length difference between the upper and lower arms to achieve the best trade off between what fits, and pinion angle gain through the travel range. Move the axle end mounts (probably only the upper) forward or back to keep the angle gain beneficial.
I hope it helps (I now need to pick up an adult beverage to drink when I get home).
