shims needed on 2wd with 4" lift?

I am having some vibration under acceleration and around 60-70 miles an hour, also when letting off the gas it make a decent clunk and when it is coasting at certain speeds it makes a pretty bad rattling type sound almost like a loose u-joint, but I checked and there was no play in them. Everything is tight back there so I know it isn't any loose bolts. Would I need some shims for a 2wd driveshaft? I didn't think I would cause it is a longer shaft but I can't figure out why I have the vibes after lifting? This is a 2000 8.25 in my 1995 Country if that helps. I know the 8.25's are noisy but I didn't think I would have the vibes.

P.S. I am switching to 4wd soon!

If you are using a stock DS with a 4" lift, yes, absolutely. Get 4 or 6 degree shims. 6 preferably. You're heading for premature u-joint failure (for a start) with the driveline angle you have.

Thought so but I just wanted to be sure. Thanks.

Okay just looked at the driveshadt and pinion and it is angled up. So I assume a shim that is put in backwardfs will bring it back down? I don't have a t-case but is the crossmember the same as the 4wd one for the t-case? Can I drop the tranny a bit or do I need to with a longer d-shaft? Sorry just trying to save the u-joints and get rid of the vibes. Bit of a newbie when it comes to setting frivelines but I need to learn for my YJ so advice is helpful.