Ok here's your answers 
The carpet deal -
I raised my tranny mount, the floor for the driveshaft, the gastank, and some 1" sections for the frame (since I channelled it and all) and I had no problems getting the stock carpet in. It was a bit thin in the corners by the kicks, but I put in some new kicks and I was good. No problems.
As for the bed... Now mine's a bit different since I have juice, but the bridge and all is the same. I did 5" on the bed. To do it, I cut out the factory fenderwells completely, and cut straight across the sides of the bed with a sawzall. I tried to make my cuts so that they took out factory dents or whatever, you know those weird indents. I then cut across the floor at the back of the bed, then across the floor at the rollpan area. All my vertical cuts are hidden in factory seams so it looked more like stock. Now I am in the process of sheetmetalling the bed in, so realistically all the work making it look factory was for nothing, but either way it worked out.
As for making sure it's exactly 5", I took a ruler and marked out a 5" gap across the truck, then used tape to mark it off. When the bed finally dropped, it went straight down onto it, I measured AGAIN to make sure I was right, and went from there.
Really the best thing to do is measure from the floor to the top of the bed a million times, and mark it. Then you'll know you're nuts on. Chances are you'll still have to shim it one place or another, but it'll be good in the end.
The carpet deal -
I raised my tranny mount, the floor for the driveshaft, the gastank, and some 1" sections for the frame (since I channelled it and all) and I had no problems getting the stock carpet in. It was a bit thin in the corners by the kicks, but I put in some new kicks and I was good. No problems.
As for the bed... Now mine's a bit different since I have juice, but the bridge and all is the same. I did 5" on the bed. To do it, I cut out the factory fenderwells completely, and cut straight across the sides of the bed with a sawzall. I tried to make my cuts so that they took out factory dents or whatever, you know those weird indents. I then cut across the floor at the back of the bed, then across the floor at the rollpan area. All my vertical cuts are hidden in factory seams so it looked more like stock. Now I am in the process of sheetmetalling the bed in, so realistically all the work making it look factory was for nothing, but either way it worked out.
As for making sure it's exactly 5", I took a ruler and marked out a 5" gap across the truck, then used tape to mark it off. When the bed finally dropped, it went straight down onto it, I measured AGAIN to make sure I was right, and went from there.
Really the best thing to do is measure from the floor to the top of the bed a million times, and mark it. Then you'll know you're nuts on. Chances are you'll still have to shim it one place or another, but it'll be good in the end.
