The Stovebolt Site Forums The Shop Area General Truck Talk Battery Size

The 6v Optima battery is a nice fit in the 47-55st battery box.
It has to be placed on a diagonal inside the box.

They most likely have a 12v battery with similar dimensions (see below)?

Here are the 6v Optima dimensions:
Model: 6V
Width: 3.63 in
Length: 10.06 in
Height: 8.13 in

Here are three pages of all Optima REDTOP battery dimensions.
(click through the dots/buttons near the bottom of each page, to see the three pages).