When I first put my lift on I had a clunking when I put it into gear and what it was is the rear-end tilting up or down depending on which gear I went into, then all of a sudden it stopped doing it and hasn't done it since. Only difference is my kit didn't have new leafs, just had the blocks and new u-bolts, maybe thats why mine did it, not sure. At least it's something for you to check on, just have a buddy watch the rear-end when you change gears.

Thanks, Any thoughts on why my drivetrain moves forward in nuetral? Or is that normal? Did a filter and flush on it two weeks ago so the fluid level is good.

Aubrey, what do you have to clearance on the front drive shaft? I dont have any binding on that one and it doesnt seam to be loose at all.

Any movement in u-joints is bad.
I don't know why you would creep forward in neutral. That doesn't make any sense to me.
http://www.skyjacker.com/image/search/pdf/D4512KS.pdf
Page 10 final notes.
Rotate driveshafts and check for interference at differential
yoke and cardan joint. If necessary, lightly dress casting(s)
and/or U-joint tabs in order to eliminate binding.
On models with a rear carrier bearing, if a driveshaft vibration
is present, insert a spacer (approximately. 1⁄2") at cross
member to eliminate vibration (see picture #38).

As for the instructions I didnt have any binding on the front and the rear doesnt have a carrier on it so there was no were to shim. I didnt have any vibrations until a week or so ago.

Ended up taking it into my Mechanic, Bad news. I have a bad u joint in front axel and my rear axel tube is bent/warped. I am short on time and use my truck for my job so had to get it turned aroudn quick. I got worse last night so I just decided to bite the bullet and let them figure it out. Going to set me back 800 on this one. I love my beast but she costs a pretty penny the older they get. I just keep thinking I am going to have a new truck soon if i keep putting more and more parts on her. :-D.

Anyone have any clue on why my wheels would spin forward in Nuetral when up on stands? I am at a loss. Thanks for your help, greatly appreciated.

I think your wheels turning when in neutral and in the air is normal, I've seen that plenty of times on multiple vehicles. As long as it doesn't try to go when you are on the ground it's fine.

Thanks everyone! Truck is back on the road and running great. They replaced all my joints and heat straightend my rear drive shaft. No more vibration!