I would have to look to make sure but I have some Deka group 31 semi batteries in my 6.2L K5(very little electrical load except starting). I got them as good used take outs way back in like 2010-2011 and they have been great. When it was sitting up until 2016 I would start it once a month to charge batteries and run up to temp and then disconnect them. I'm surprised they are still good and worked fine all through winter even with the cold temps and harder starting up here.

