Help ID a833

OK, WHUT?? ............is a "command box?"

Only 3X low gear 4 speeds I know of (non OD) were some slants and 273?

By the way I don't think the 3X low gear boxes are particularly strong, either
Edit; Commando box; the 3.09-1.92-1.40-1.00 box as found behind the 273-4bbl Commando engines. My 360HO streeter has not been able to damage it in the least yet, in something like 60,000 miles or more, with thousands of full-power 7000 rpm powershifts.