Looking for a new replacement 12 Volt battery for my 1957 Oldsmobile Super 88 2 Door hardtop. Walmart = No Good, Orielly's Auto = No Good, Auto Zone = No good. Rock Auto = No good, None of these will fit the battery tray and are too tall for the factory negative cable that hooks to the block and the battery tray. Battery Central Mall = $400

Any inside info on where to get a battery that won't cost $350-$450 that will almost fit the battery tray. Dimensions are 13.5 inches long, 6 inches wide, and 7 inches tall. Could go as tall as 7.5 inches but that would be it.
Any help or thoughts?? Most batteries are too tall and too wide.

 

If you need a battery that is exact for a Con Cours restoration the high priced one is your choice, I think. If you just need a battery for function, take your measurements and a tape measure with you. You can probably find a current battery group type that can work.

Here is a chart to help you.
https://www.jegs.com/Sizecharts/bcig...xtrJC7RGaHbxuH

 

Did you consider a Group 27 size battery?

 

Measure the space available and the size of the battery in it now if there is one, then look at battery dimensions on a BCI group size chart. Also look at the electrical specs for a comparable cranking amp rating.

 

What group size battery is in it now?

 

Had an Exide Classic Part # 65C Group Size 65 but was too big and have to have a tarp strap to Hold it in.
Was hoping to find a reasonably priced battery that would at least fit in the tray.
Tried taking measuring tape to several different places but no luck.
Best luck I have had is at Titan Machinery in South Dakota which is a tractor implement dealer. That is where the exide battery came from and wasn't too bad but looks tacky at car shows when you open the hood.

 

Group 27 are all 8.75 inches tall and that is too tall for factory original ground cable.

 

Buy a longer ground cable and all the battery sizes will work.

 

The original battery in that car would have been an R63, which is a Group 60 case. 13" long, 6.25" wide, 8.25" tall. Unfortunately there are no readily available batteries that fit within that envelope. A Group 51 is narrow enough but is 8.75" tall (9.375" long, 5.1" wide, and 8.75" tall) . You might want to consider changing the battery cables. Also note that the Group 51 comes with standard and reversed terminals, so be sure you get the version that puts the terminals in the best orientation for your car.

 

OP should have no expectation that drop in, affordable, good looking replacements are readily available. Car is 70 years old. Recommend seeing what the 30 billion tri five chevy boomers do.

 

I got mine at Costco for my 57 and it is an interstate battery

 

What group?

 

Mine was group 24

 

x3 on replacing the battery cables. If they're OE they're probably due for a replacement anyways.

I just put 2 Group 27 batteries in my 86 Ford F250. If they're strong enough to turn over a diesel engine with 22.5:1 compression they'd work fine for your Oldsmobile if you could get them to fit.

 

There ya go, @snowmonkeys . Just compare the measurements of that battery with the measurements Joe so thoughtfully provided. Hopefully it'll work for you.

 

I am a pretty old and simple guy. Ya,,,,,,,,,,just a little wider, but, it works fine.

 

As you can see, my braided cable worked fine, close, but fine. As Ralph and Olds64 said, just buy a longer cable. Possibly one like this,,,,,,,,, https://www.ebay.com/itm/196197950382?_