Nos y 59

[x33rs]

Reverse polarity is what the stores call them. It's simply just the + and - terminals switched from side to side.

Early 69 Z's such as mine have them reversed, so the negative is closest to the radiator which is the Y55 battery. From what I understand, maybe sometime in Jan or Feb GM switched to the positive closest to the radiator which is the Y59 battery.

So to answer Ban's question of Y59's being correct for 69 Camaro, a build date makes a difference. However I can't recall if this is a Z/28 thing or all Camaros in 69.

One interesting way to tell (if the car is largely original), the ground wire off the ground cable went to the core support on the Y55's, and on the Y59's I believe it went to the fender.