weird sound on the Nova

I just got a 1970 Nova and when I turn on the car there is a sound on the motor or something that sounds like Tack tack tack.... but when i step on the gas it goes away. What can be the problem?

get used to it...lol... its a old car

Need more info. Does it only happen when the cars cold? Go away when it warms up? Or does it only go away when you rev it up? Where does it sound like its coming from if your standing outside the car? Can be a few different things, but my gues would be you just have a lifter tapping and you may need to adjust your rocker arms. May also just be a blown header gasket. I highly doubt its something major, probably just something in the valvetrain.

Rob