im new here and in need of some help.

[FnStrkn6.4]

have a ccsb 6.4 4x4 was lifted and now lowered with 5.4 set up, up front and no blocks in the rear with a one piece shaft. im having a really bad vibration at roughly 68-78mph before and after is nice and smooth. the tires and balancing have all checked out and the shaft has also be checked and all is good. i really want to get this figured out. any help would be great.

 

[SouthFlstrokin']

What's your driveline angle?

 

[FnStrkn6.4]

trans is about 4.6 down and the pinion is about 4.5 up

 

[SouthFlstrokin']

Hmmmm, I had the same issue once, had a bad tire...