Anyone have the correct battery size for a 1972 Cutlass S 350 cu in? Battery group in there now is a 27F which I do not think is correct. Looking for recommendations please.
Dan

 

Duralast Gold 78-DLG is what I have in mine

 

Your 27F is incorrect as it has reversed terminal location.

· 1972 350s with HD battery option used the R-91, a side-terminal battery. This is a group 27 battery, 12-inches long
· The 1972 350s without HD battery option used the R-89, also a side-terminal battery. This is a group 24, 10 1/4-inches long.

 

Thanks Gary. Definitely the wrong battery in there. 2 inches longer.

 

You're welcome, Dan.

But are you sure your car wasn't ordered with the 12" long Heavy Duty battery? It would show up on the dealer order or on the window sticker. And, depending on the assembly plant, on the build sheet.

 

Build sheet says it is an R89 battery which is the shorter battery 10.5 inch. However the cables have been changed to post type instead of side terminal. Somewhere along the way someone replaced the small battery with a heavy duty one and swapped cables.

 

Good to see that you've done your homework.

Just a note to assure you that whatever new 10 1/4" battery you choose, it will have far more CCA than even the optional 12" battery had back in the day.

Here are specs on the factory batteries:
R91 - 73 amp hour, 390 CCA
R89 - 61 amp-hour, 350 CCA

 

I got a battery that matched 1) the size of the tray and 2) the battery cable terminal ends (top post).
For my car, that was an Interstate Group Size 24.