Have a friend who needs suggestions for a new battery in his 67 911.
Battery sizes have always been confusing to me.
51R?
Would prefer an AGM - needs to be drop in, plug-n-play.

Thanks!
Brian

I'm a Interstate Battery dealer.

The sizes 51/51R will fit in what the internet says the original battery size was

Both are
L 9 3/8
W 5 1/8
H 8 7/8
The R just changes polarity on the terminals.

An internet search should get you a diagram to determine which way the terminals are placed.
These are normal shaped base. Just a battery.

another size that looks like it will work is 121R.
L 9 3/8
W 5 1/8
H 8 7/8
This thing has a different shaped base for specific mounting. They have flanges on the bottom.

I've got AGM available in the 51R size only.
Interstate part number is MTX-51R.

My "official" price list shows a retail for that at 254 and a cost to me 20% lower.

Gives you some idea of what this should cost.


The specs for the original 2HN are supposed to be:
L 10 3/16
W 5 1/4
H 9

At one time Interstate sold a 22NF which was closer than a 51 but is no longer available.

Hope this helps.

A 51R is a little car battery. Think Honda Civic

Excellent info - just what I needed - thank you!