Unfortunately the axle code doesn’t help because it only tells the axle maker and ratio. My van had the #34 axle code and came with the full float. What year and configuration are you looking at?
The 6,084 Rawr is simply the rear tire rating for 245 tires. The axle will be rated higher even if it’s a semi-float. 6,400 and change if I remember right for the D60. The FF and SF D60 have the same rating, it’s just the SF doesn’t tolerate overloading as well and has a potentially dangerous mode of failure when the bearings wear out.
The D70 full float is good for 7,800 pounds. That’s what mine came with (also with code 34).
2000 E450 dually V10 wagon