Installed rear lift, vibes gone - soooo happy!!

Well, came home early from vacation yesterday because of crappy weather and had a box from Wheelers' waiting for me. I got a 1.5" 3 leaf progressive aal kit, rear 5100s' and had a like new set of tsb springs waiting in the garage that I'd bought from a member several months ago. I figured I'd just install the aal on the leaf pack so it'd be ready to go for today and I just kept going. Everything went really smoothly ( I was really expecting the leaf spring bolts to be seized in and they came right out) with the exception of having to cut out the factory shocks as the top nuts were rusted in place. Result - Happy Happy Happy!!! I took it out for a drive and it's perfect, smooth as could be. No vibes anywhere. I previously had vibes from 40 - 45mph that could make me nauseous that I thought might be the carrier bearing. Gone. No take off shudder, no vibes, just great. From previous measurements I'm up 2 1/4", from 35 1/2 to 37 3/4. Now to get some 5100s' for the front real soon. Not sure if I'll put them at .85 or leave them at 0 as the truck looks like it has the factory rake now which is fine with me, I don't want to mess with perfection . Oh, no shims were used, and overload was left out.