Both of the links you posted have transmissions that are misidentified. Again the 47RH was a diesel and V10 only transmission for the 94-95 model year. They are all lockup style. The 47RE and 48RE were diesel and V10 applications only for 96 MY and up until they stopped, all lockup style. The 46RH/518 was for gas engines 88 or 89 (I forget exactly but the early ones had smaller 5/16 cooler lines) and up and diesels 91.5-93. They came in lockup and non lockup styles. All the diesel versions were non lockup. So unless you have a 5.9 Cummins in your van you don't have a 47RE in it, you have a 46RH if it's hydraulically controlled or a 46RE if it is electronically controlled. You can put some of the 47/48 internals into a 46 case but not everything.
The diesel and V10 bell housing is large and accepts a larger diameter torque converter. The converter also protrudes from the face of the bellhousing about an inch or so when fully seated vs the 1/2" the converter is recessed into the face of the bellhousing on gas versions and non lockup diesel versions. It's not because the bell is cut back, it's because the converter is thicker to accommodate larger, heavier duty components.
You could cut the bell off a 46 or 47 and use an Ultra Bell for a 727 to B/RB pattern or an adapter for the 46 gas engine trans but you are still stuck with the smaller and narrower converter. That may be fine for your application, I don't honestly know. My concern would be the durability of the smaller converter and lockup clutch to handle that weight with that kind of wind resistance as well. It will always be under load.
I burned through a stock lockup clutch with my slightly warmed over 12 valve pretty quickly and I wasn't even towing with it yet. I'm probably only making about 500 lb/ft. I put a single disc billet cover converter in it and it's been fine since even with some pretty heavy towing.