Group 31 battery questions

[Iceni John]

Thanks for all your helpful replies, everyone.   I think I'll buy the O'Reilly 1260 CA batteries:
http://www.oreillyauto.com/site/c/detail/SSB0/316T.oap?ck=Search_N0369_-1_-1&pt=N0369&ppt=C0327
They are $136, plus only $12 core charge (I'll be keeping one or both of my 8Ds for now as temporary house batteries), and they have an 18/36 month warranty.   That's not much less amps than my 8Ds.   If anything goes bad with them, I need only go to the closest O'Reiily store, and they're in lots of places around here.   (I know that Sam's Club / Walmart may also have suitable batteries, but I will not spend my money there.)   Interestingly, the O'Reilly website says that these batteries have separators to protect the plates on all four sides  -  I wonder if other lower-amp Group 31s are made this way?

For now I don't have my house battery system, but when I do it will definitely use some of the 4/0 cable as an emergency tie-in to the starting system.   I've got almost 80 feet of 4/0 now, so all the electrical systems will use good cable.

Thanks again, John