I agree with the idea of switching to truck-type threaded stud battery. Post type clamps are terrible to work with, I think. 

My question here.....will a grp 31 battery fit into the battery box of a xx30 or xx40 tractor?

I wish there was a "clean" way to add a battery box to an xx20 tractor to convert it to grp 31. I realize you can bolt a box on the frame, but that seems to be the only choice?

Thanks