Update: i took my truck to get the rear leveling kit installed, i took a 2in and 3in leveling kit so that the experts could decide which was best to level. well they just installed a 2in on top of the stock lift giving the back a 3 5/8 lift...... the tire shop told me thats how they install rear lift kits because they add on kit wont sit on right without the stock lift... is this true? every video I seen online shows the stock lift being remove before adding any other lift.

 

never stack blocks, you may not ever have a problem but that goes against the industry standard. my 1.5" AS kit raised my front 2". I spoke to Auto Spring and they sell a 2.5" kit but actually they didn't recommend it on our trucks. if you plan on towing with your truck I would not stack blocks.