clatter noise. like noisy lifters

I have a 96 dodge ram pickup 390
150,000 clicks
Makes a clacking noise when it starts to get warmed up, like dry lifters when you are low on oil.
Heres the kicker, when you first start the engine there is no noise until the Temp. gauge starts to move!

Engine ping. It can be fixed by doing your plenum pan and intake gaskets.