the 3 cylinder 224 and the 3 cylinder 284 are the same, exact chassis. same tires, same loader mounting brackets, same size, period. i have 3 of the 224's now, in stock, and 2 of the 284's left. (LE versions), and they are the same. only difference or variation possible is if tractors are ordered with turf tires instead of ag tires, there is a difference in the fiberglass fenders, particularly the size. if you order tractor with turfs, then ag tires will not fit on them, but if ordered with ags, you have plenty of clearance to install turfs.
i do not know specifically the exact weight, but i can't see how there would be absolutely any difference in the weight.
when i get time, i may just run 2 of them down to the local elevator just to find out for sure, but then again--when will i find time??