What group and size does a 1962 Olds Dynamic 88 take? Original 394 V8

 

Original was a Group 60K which is only available reproduction now. A Group 29NF Ford style battery is roughly the same size and a little easier to find at a farm or equipment supply if you aren't after 100% original appearance.

The 62 battery tray is a little more forgiving size-wise than a 63-64 tray so you may be able to use an even more readily available battery.

Battery size comparison chart:

http://www.rtpnet.org/teaa/bcigroup.html

 

Group 27F is what I use in mine. Very close to the original dimensions.