I just finished installing a 2.5" front leveling kit from Tuff Country, and a rear
add a leaf from Rough Country. Both were straight forward in installation
and both came with decent instructions.
Times for install was;
Front leveling kit 2.75 hours.
Rear add a leaf kit 1.5 hours.
Truck looks great, ride is "stiff".
I did not incur any unexpected problems.
All was done on my lift, not on the floor.

Overall, good project, with satisfactory outcome.