Interstate mega tron plus 24 or 27, for the money hands down the best battery you can buy...

I have used them in everything from heavy equipment to my wifes hybrid, there is no reason to spend more on less, never had an issue, I havent used them in many daily drivers since I buy new cars and only keep them 3-4 years max, but I have used them in other things and had them sitting on shelves for years then installed them with out problems.
http://www.interstatebatteries.com/b/vintage-car/1970/dodge/coronet/N-zihwpmZzihwp2Z1z0twgiZ1z0ttxgZzihwsq?dsNav=A~Part+Number&1=1