There appear to be typos in some owner's manuals. Some list even-numbered batteries, which were OEM, and not available for service. Some don't seem to properly identify side-terminal batteries. (Various apparent mistakes were found in the '71-'75 owner's manuals-another example of why you can't always trust factory literature, or photos, for that matter.) Also be aware that the suffix "S," like in R59S, doesn't mean "side-terminal"-some people think it does.
I believe there's a misperception regarding reproduction battery life. Our classic cars sit much more than our daily drivers, so the battery charge needs to be maintained by another method. Smarter battery chargers fit that bill. I heard about the Battery Tender 12V DC output at 1.25 amps from my son, and I've been using it for battery tending ever since with outstanding results and fewer battery changes.
Let's talk about judging. I've always felt that one of the easiest places to gain or lose points is the battery. (I also feel that an original-type battery enhances a stock, popular-vote car). In POCI points judging, you can lose up to five points for the battery.
Take my '71 1/2 GT-37 for example. I had the heavy-duty battery option, R59S. It isn't reproduced (maybe some vendor should reproduce the R59S top label), so I have an R59-the closest you can get. If the same car had a 350 two-barrel, the standard battery was a Y59 (yellow paint on the top caps versus red on the R59), but it's not reproduced, either. The best you can get is an R59.
As a member of both the GTOAA and POCI Judging Committees, I encourage the judges to award full points on restored cars since the owners have done the best they can. "Original" cars can go the same route, or a modern Delco-Remy equivalent replacement to the original battery can be used.
What about modern cars? I'm starting to regret turning in some of our used batteries as cores. They could've been saved to show the correct exterior appearance for future reproduction purposes. (Yes, people will collect "modern" cars in the future and some of the following comments apply to Firebirds, for example). Some modern Pontiacs, such as the Vibe, came with batteries labeled as Delphi, not AC-Delco, which is apparently related to the spin-off by GM of its parts operations. These batteries appear similar, however.
Do you remember that the original "Freedom" Maintenance-Free batteries had blue tops, white cases, and multi-colored top decals that included red? (I hope my memory is right on this). The battery top also had two "penthouses" and an eye.
At some point, the top color changed to black and the decal colors also changed. I believe the OEM battery cases stayed white and the service cases were eventually black, as well. The OEM battery number and the replacement battery number, which were different from each other, were on the decals on top of the case at some point. Eventually, the "penthouses" disappeared and the top of the cases became "flat." Then the "eye" was eliminated.
Recently, the top style changed again on the newer AC-Delco batteries. I believe the AC-Delco Professional most closely resembles the original "Freedom" style, except the cases are now all black. This may be the best modern car owners can do.
Dealers only stock a certain number of batteries, and if you need a warranty replacement, it looks like you get one with equal or greater CCA than your original, which may not look the same.
I want to briefly talk about CCA-at 0 degrees F, specifically-and reserve capacity. CCA gives some idea of how powerful the battery is. Higher CCA batteries are better, tend to last longer, and are usually heavier. Some people have hot cranking problems with their traditional Pontiac V-8s due to too little CCA (455s are the worst).