'67 912 Battery Question

[711wildcat]

Looks like I need to replace another battery. I am curious if there is a max cold cranking amps (CCA) specification for the '67 912 engine. I've noted my prior two batteries were 425 and 450 CCA, respectively. The Optima (which also failed, and was installed prior to the other two failed batteries) was a 450 CCA as well. Any feedback on great battery experiences and if one can place, say, a 500 CCA battery in the beast would be appreciated!

Also, I am considering a quick disconnect for the battery - any thoughts?

Background - car is always garaged and not subject to extreme heat that may otherwise diminish a car battery life. So the reason I am going through a battery every other year is somewhat puzzling...Thanks!

[WFBowen]

First, I'd definitely install a battery disconnect as it seems something is "leaking" charge from the battery. The number of failed batteries you mention is not normal. My 912 sits undriven for weeks and fires right up with a cheap no-name battery that's on its 12th year in the car.
I'd invest in the biggest CCA that'll fit in the car. It doesn't have to be a designer brand. Then have your charging system checked out (I assume you still have the small generator in place.)
Also, try to isolate any circuits or equipment that is drawing when the ignition is off. You can systematically go through the fuse circuits individually and then check hot leads going to the relays for lights, especially those that stay "hot" with key off. Check any "unknown" wires or ones that don't look like factory ones - especially any alarms from previous owners.
Good luck
Bill