I appreciate that. I've been looking at dimension numbers on the different battery groups and trying to figure out what works. However, when I look at specific batteries, it seams that batteries can vary by size a little even within a group.
I'm starting to think that maybe a 51R will work for me. The height was my biggest concern. I don't have the factory tie downs, so I have to figure out something on that end anyway. I'll probably just us a rubber strap.
I appreciate you measuring your batteries. That helps. Thank you.
You want the battery to remain as stationary as possible, flooded cell batteries don't like being jostled around.
What I'd do is go to the auto parts store and buy a battery hold down kit (they all have them) for less than 10 bucks and adapt the kit to your desired battery. All batteries produced today (with the exception of small lawn and garden batteries) have built into the case, molded tie down points, usually at the bottom of the battery case. The hold down kits engage those tie down points and will secure the battery from movement. You might have to drill a couple holes in the battery tray to accept the hold down hardware but that is a lot better than a tarp strap.
Just added a second batter to my wife's suburban. TYhe tray was in place but no hold down hardware or cables. Bought the hold down hardware at Autozone, bought the appropriate lengths if stranded welding cable at Tractor Supply (they sell welding cable by the foot in various AWG gauges) and the lugs from TSC as well. Tinned the cable ends and swaged on the lugs and viola, I have the second battery installed.
