Camburg 4'' spindle lift

Hello, I'm ready to purchase Camburg 4" spindles yesterday but want to see if the rims I bought the truck with will work with them for a few months till I can get new ones? I don't know the backspacing or the offset of the rims i currently have bc they were on it when I purchased it. They are 20's. LOL I'll probably call them Monday but cant wait and figured someone might know. My tires are 265/50/r20. Thanks

 

I believe that Camburg recommends a 4.5" back spacing. You should be good on the rim size. I am running 18" Monsters 4.5" backspacing and a -12 offset. You are better going with a bigger wheel because of the clearance with the center hub of the spindle.