if you can fit it in there a group 31 battery is always a good choice. I have had really no luck finding one brand that is so much better than another brand, it is hit or miss, the glass mat batterys should take vibration better but you better sit down when you price them. we got a Rural King here and they usally got better prices than other stores.
Thanks David, for the information. Since placing this post I have looked into batteries and you are right, they are expensive. But I suppose it is a good investment. My bulldozer takes a lot of the physical labor off of me. I am still trying to decide which name brand to buy. Thanks again for your input.
It might be worth going by or calling a heavy machine or tractor dealer, manf. should not be a big deal who it is ,and pick their brain as what they think of glass mat batterys before you make that investment. I did work on a yamaha 4 wheeler the other day and you know they get pounded and it called for one in there. But as small as that battery is it was still 75 bucks .