Combines swapping 32

You could put 28l x 26 on your 1440 without any changes, you can move centre pivot brackets on rear axle to compensate for lower tyre height, but I would stick to 24.5 x 32. The 28,s have to many problems with walls cracking,etc.

Goodyear handbook shows flat plate contact area for 24.5 is 363 sq in and 28l is 373 sq in. I would stick with 24.5 because it is a taller tire(71.8 in vs 64in) and will roll easier on field.