6.5" is an approximation. You bed will be roughly 6.5" higher than it currently sits, but that's relative to how it is now. If you somehow added a 6.5" puck to the front, then the truck will sit level (assuming it sits level now). But you'll be adding brand new coils to the front. And they are likely to lift the rated amount, but that doesn't mean they will necessarily match your current leafs, which may have sagged a little over the years like mine. Personally, I'd go with a 4.5" to 5.5" lift kit, and if the rear end sits too high, I'd either add a little pick to the front, or throw some crap in the bed like a truck is supposed to have. Bottom line, it's hard to predict how your truck will turn out when using 20 year old leafs.
Oh, and the metric/big/heavy ton package sits about the same height as a regular 4wd MJ. But it will better resists settling after you add the big spare tires, gear etc. Also should resist spring-wrap better. :thumbsup: