knocking/ticking on deacceleration?

[Iand]

I seem to be having a bit of a problem, when i let off the gas after accelerating for any given amount of time my engine starts to make a ticking or knocking sound from the right (sitting in the car) side. Almost sounds like the valve lash is out of spec? or maybe a bent pushrod? Ill tear into it when i get the car back on thursday...just curious what might make that sound.