Farmall Cub

My '47 cub that was converted to 12 volt is in line for a new battery this year. The old one is a regular car battery and therefore the battery case has been butchered. My better half bought me a new one for Christmas and now I want to get a battery to fit into it. Keeping the tractor 12 volt. Any of you guys got recommendations for what to buy? Parts numbers help.
Thanks,
malcolm

Just check a battery group size chart. Find something smaller than group 1 in all three dimensions with top posts.

I think group 54 is a top poster.

http://www.rtpnet.org/~teaa/bcigroup.html