Originally Posted by jcyuhn

You can use the optima battery in a 124. I've put 'em in both 124 and 210 chassis cars. Fits fine. You just need the reverse post model - used to be the orange top, but now I think they just make a 'regular' red top and a reverse post red top.

The optima isn't as wide as the standard MB group 49 (or is it 48?) battery, but it's about the same height and the depth is the same. It will fit in the battery tray just fine, and the standard MB hold downs at the foot of the battery will work fine.

- JimY