The 3000/4000 Twenty brochure also has an asterisk on the 400CX (self leveling) stating that it would be "Available summer 2005".
For what it's worth, pages 4 & 5 of the brochure show a 4000 Twenty tractor (can't see the exact model number) with a backhoe on it (presumably a 448) and a 400X loader with pallet fork carrying a pallet of sod. The sod appears to be stacked starting at 10 rolls on the first tier, 8 on the second tier, 6 on the third tier and 4 on the top tier. I have no idea if that constitutes a "standard" full pallet of sod or not.
Also FYI, here are the loader specs listed on page 14 of the brochure (note that ALL specs are given at the PIVOT PIN, not a realistic numbers IMO):
400X
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Lift capacity, max height, at pivot pin: 2,368 lb.
Maximum lift height, at pivot pin: 112.8 in.
Breakout force, at pivot pin: 3,506 lb.
400CX
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Lift capacity, max height, at pivot pin: 2,194 lb.
Maximum lift height, at pivot pin: 110.9 in.
Breakout force, at pivot pin: 3,512 lb.