Interstate Batteries rock. I just put one in my '79 300SD. I use them in all of my cars. Interstate batteries just bought our local "battery patrol". Their website is:
My battery cost $85.00 at my rather pricey import parts store.
I have had good luck with $35.00 Exide batteries, but would not put one in my diesel.
Sears batteries depress me. I have had more duds than good ones. I used to depend on them solely for my car batteries- big mistake.
My Mercedes dealer and the local tech's all use Interstate.