Decided to go with 37s, but have a question?

So I made a post in here to help me decide which size to go with 35s or 37s, as I will need new tires very soon. After looking at views and also hearing from people in person, "tires look to small for the truck", I have decided to pull the trigger on a set of Nitto Trail Grapplers in 37x12.5r20. I will be regearing shortly after too 5:29s, but I am curious with my specs, how much chopping will I need? My current specs are a full 6" lift with BDS UCAs. The wheels I have are 20x9 with a 0mm offset. I'd like to stay at 6" and don't want to go up an inch, but if it will help me greatly, I'd be willing to get the coachbuilder 1" coil spacer and shackle kit. But again, I'd like to stay at 6" because I feel the CV axle is already at a steep angle. I am perfectly inclined to do a BMC and I am totally not scared to do that, but ehat about the other things like the pinch welds and plastic. Will those need major modifications? I am completely confident in any kind of mod work, I guess I'd just like to know just what I'm getting into. I worry because the Nitto Trail grapplers run wide and the offset is above the +25 BDS recommends. Any advice, pointers or insight is GREATLY appreciated as I am learning this new world of lifting trucks and not lowering lol