I made my own the same as the perfex kit
With factory tires running 29” tire I did find it best to run spacers 1.5 in the rear an 1 in the front kept them inline with the body
the tires tuck in a bit more then they already are with the lift
But in saying that a never checked if they rub
I have aftermarket rims 5+2 offset I think an 30”tires now an I just run 1” in the rear
Not a great answer I know but hopefully helpful