I would say that you NEED to recurve those leafs ... no reason to have 6" blocks for 35"s . I only have 3" blocks in the rear.
Blocks that tall might pose problems ....might be better to open up the wheel wells so you dont go that tall ... top heavy pose problems offroadin ...like on the side of a hill.
The TALLER you go the WIDER you MUST be...
This pic is from the accident repair ...
See where the govt welded a 2" bar across the ft and put the shackles n leafs on that bar ... that is considered a body lift and look below a 1 in block under the leafs. 3" total but it fits 35" tires