Well i got my 6 inch superlift bolted into my 76, now the fun process of workin out the bugs is at hand. I have already put in the 78 solid drag link style steering, but as the radius arms are now angled down, even with the drop brackets, i now have 2.0 degrees of negative caster, which makes a very bad driving experience on the highway. I have a wicked vibration on acceleration under 20, so I tried dropping the hanger bearing to no avail. I will probably just get a one piece shaft built. The front shaft binds at the transfer case yoke slightly at ride height, so I will try clearancing it and see what happens. I may have to get one built for the front with a cv. My truck also has an unusual sag at the RF corner which was increased 3 fold with the installation of the 6.5 inch lift springs. I am thinking of drilling new holes about the amount that the truck sits lower on that side to move the tower down and level the beast out. Also does anyone have any suggestions for a headlight system for use in the city? The factory beams aim into other peoples faces even when they are in stock height pickups! I was thinking of mounting some aftermarket cheapies under the bumper just to get the height down, but also dont want them to low as I will rip them off promptly when I go wheeling.

 

I'm tired so I'm going to be spacing a few things off here but I'll give you my thoughts:
Did you install degree bushings where the radius arm meets the axle? You didn't mention it so I assume no. This is a must to correct the caster angle. The bushings are cheap and install quickly. The downside is when you fix the caster you'll bring your pinion lower making your front driveshaft angle even worse. Good luck with this project! You can either have a double CV driveline made or you can do what I just did and turn the C's on your axle so you can point the pinion at the T-case and still have proper caster. But that's a big PITA and you better have the right tools and a lot of patience.

I would bet money that the vibration you are feeling is U-joint related. Is your rear pinion pointed directly in line with the driveshaft or is there an angle there? If you have a goofy angle this could be causing the vibration. Degree shims can fix this problem. If you don't have a goofy angle check all your u-joints to make sure you don't have a bad one.

For the headlights, just adjust them. They only blind people if they're pointed incorrectly. You can do this with a ricer and headlights 24" off the ground. Mine are 57" but they don't blind people because I adjusted them down.

As for the sagging corner I really can't say for sure but don't do what I did and build your whole truck lopsided because you forgot to check tire pressure. Check to make sure all 4 tires are the exact same PSI. If they are and you still notice that corner sagging I'd venture a guess that your frame is tweaked.

 

Yes, The bushings included with the lift were offset for caster, but it still runs -2.0 on the machine. As for the driveshaft the rear yoke is pretty much strait, but in school they say to run the angles within 0.5 of a degree of each other, so I think the differential between the u joint anlgle may be a cause. The sag is definitly not tire pressure as it sits about 2.5 inchs lower on the passenger side.

 

That's what I said about my driver's side. Then I fabbed up special shackles and had it all fixed until Pro reminded me to put air in my tires. Now guess which side my truck leans to? I'm not saying it'll solve your problem but be sure to check it. Otherwise your frame is tweaked. If that's the case you'd better get used to a lopsided truck.

If the U-joints are in phase you can run them within a degree of each other as you were told in school OR you can run the pinion at a 0 degree angle. If you run them both at an angle they have to be matched pretty much identical which is hard to do and this also means more strain on 2 joints vs. only 1 joint that has to work at a tough angle. Also, if you raise that pinion you'll find it slightly decreases the angle at the T-case too.

If your caster is still -2 degrees then the bushings you have in there are not the right bushings. Call the manufacturer and see what they can do for you there. 6" is not a huge lift so it shouldn't require anything too fancy to acheive proper caster. I can't believe you're having this problem even with the radius arm drop brackets. Is it possible the new degree bushings may have been installed upside down?

 

No, I installed them front, bottom, rear bottom, etc. i think i may just leave it as is and run it off road only.