What Year Valve Cover?

What's shown in that pic is a '61-'65 cover. There is nothing wrong with either of its two chimneys; the rear chimney is supposed to be shorter than the front one. The '66-'69 covers are similar except the short rear chimney is replaced by a flat hole and grommet, and the heater hose bracket is bigger and sturdier. The '70-'80 covers have three flat holes, one of which has cam ears for a twist-lock oil cap. All '60-'80 valve covers fit all '60-'80 heads. The '61-'65 type (shown in this pic) is something of a nuisance as regards the PCV valve these days, but it's not a showstopper by any stretch. Note that if you have a '60-'62 car not equipped with PCV, and for some strange reason you want to keep the primitive, ineffective road draft tube instead of retrofitting PCV, you must use a '60-'65 (2-chimney) cover.