WOW! Twelve years?!
I replace mine every five years, if it even lasts that long.
Well, the whole truck is near stock, and it's an 87. We were at Dad's mechanic last week having the oil changed (it's a requirement of the gift that we have the oil changed and all work done at that mechanic) and dad was asking him what all we might want to do as far as tune up. He said... well, these are the original spark plug wires, look, they've got the factory dates on them. only the original wires have dates on them.
And they're clean. And they're working just fine.
So if anyone can make a battery last 12 years, it's my dad.... though I'm surprised he did... He'd be just as likely to replace it every year just to be safe. That one could have gone either way.