Here's a
link to my past thread asking the same question, with a lot of reviews from other members. I recently purchased a Red Top Optima and absolutely love it!!! The first time I dropped it in the '72 it turned over like it never had. I bought my at Sam's Club and beat every price around (O'Reilly, Advance Auto, Auto Zone...). The price is a little high, but with some of the reviews given, and the fact that my truck is only driven every so often, as well as to car shows, I figured the life of the battery would be longer than any regular battery. I do disconnect after each time I use it, just in case the '72 develops some type of drain.
There are plenty of other batteries that will do a good job, some a lot cheaper, but with the amount of time this thing could sit, I liked the idea that it will hold a charge for a long time.
Just my $.02...