06 F250 CCSB 6 inch Fabtech question!!

[LBCpowerstroke]

Ok first off I got a 06 F250 6.O CCSB and I think it has the 350 suspension Had a stock bout 2 inch rear block with bump stop cuhz before I even lift it, it would clear my 35x12.5x17 Toyo mt on stock wheels, ok on the the lift kit.....so I jus installed a Fabtech 6 inch radius arm system on my rig today when I take off from a stop/light I get this vibrating/shutter at 5-20mph then from there smooth?? I jus shimmed it but haven't drove it yet so we'll see tomorrow......but my question is what do u pros think bout the block setup Fabtech uses??? I really don't like the setup jus cuhz the ubolts are so long and seems not sterdy.....it rides kool but I sorta feel like it sways jus a tad bit tho not alot, I have really took it around bumps and stuff I jus hope it doesn't feel like my rear end or front end is gonna fall off lol.....I made sure all bolts were real tight and thread lock every single bolt I remove and replaced most bolts were blue threadlock besides my pitman arm which I used red thread lock. Ok would I be better off getting a 6 inch rear leaf pack setup or would what I have be coo? And what's the best brand of 6 inch rear leaf pac to get and smooth ride hate the stiffness! The stocks feel

[LBCpowerstroke]

Ok well I still get a vibration from 5-25mph then it's goes away and on the fwy at about 55-60mph I get the same feeling.....I shimmed about 1 1/4 down I'm going to get a new carrier bearing(center support) my rubber bushing look pretty f***** what u guyz think?

[LBCpowerstroke]

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