I don't think you have a long arm lift if you are using the stock lower arms. Anyway, here is a writeup that will help answer the caster question. You will need adjustable arms to be able to adjust caster. Basic Do-it-Yourself Jeep JK Wrangler Front End Alignment

 

I mean i have skyjacker lowers and stock uppers

 

My squirles went away after getting the castor bumped out, also lowering the tire pressure helped some. The big tires have ADD sometimes, oh look a crack in the road whats that over there an expansion joint

You have alot of lift, you may want to look into the TF drag link flip kit, you may just need some geometry corrections.

After seeing your last post, you may be in the market for some adjustable upper arms

 

Oh Jeez, your caster is probably about ZERO degrees. No wonder your JK feels skittish! You need adjustable lowers; or better yet have adjustable uppers and lowers. Start with the uppers 1/4" longer than stock arms (to preserve your wheelbase) and adjust the lowers to 6 to 7 degrees if you have a stock driveshaft and 5 to 6 degrees if aftermarket and see how that feels. Making the bottom arm 3/8 longer than the stock arms would put you in the ballpark. Then take it back to the alignment shop. But don't letthem use stock specs. And if they insist it go out at stock specs slip the guy a 20 and have him tell you how man turns out it ill take you to get to 6 degrees and adjust them yourself at home. You'll be amazed at the difference.

Just because you can fit 37's on a JK with non-adjustable arms doesn't mean you should; or that it is safe.

 

I don't know much about your lift so I will take a few guesses about your control arms. If your lift came with fixed front lowers it was to get your axles re-centered in you wheelwells to correct wheelbase, if this is the case and you are still using the stock uppers they are going to be way short. It is possible at this point that you have - negative castor. If this is the case I am sure your Jeep drives like hell. If the assumptions are correct you really need to get some adjutable uppers, it will make a huge difference. Control arms are not cheap but lifts of your size really needs them, it is almost unavoidable.

My story wan't to complicated, I installed the TF lift and had both upper and lower arms, I just had the uppers to short when I did my install. I took my Jeep to a company in the STL area called Axleboy and he dialed in my castor up front and my pinion angle out back. He actually streched the wheelbase a little to help with the pinion angles. for $150 it was well worth it for me to do the heavy lifting with the installation of the lift and have him do the finesse work.