eibach/5100 lift vibration question help needed

Hey guys I have searched and found lots of info and mixed reviews and posts on this, sorry to ask but I recently installed the toy tec lift eibach billstien lift with lift blocks and different drop, I'm getting a vibration or almost like a shudder from 40-50 mph, the tires are brand new and all balanced and rechecked twice to make sure, also had a alignment, I even tried spacing the carrier bearing down 3/4 inch down, also all u joints seem good and every thlngs greased and checked and carrier bearing seems to be fine. Truck was fine prior to lift, and thoughts or do I need that different drop that people are running on the carrier bearing ? By solid taco or some name? Any help would be great thanks TW!!

 

Anyone? I'm sure others have had this and experienced problems ...I just am not sure if the street taco carrier drop will resolve this completely or not .....I already dropped the carrier 3/4 but street taco looks to drop it more ?