[Chevelle-List] Strange Sounds!!!

[Lojac]

I have a 69 Chevelle with a 396 and I have two questions about some strange sounds.  When I start my car there is this clicking sound that sometimes goes away after the car warms up and other times you can really hear it when the car is idling...any ideas as to what is causing it (worn out lifter mayby)?  The other sound only occurs when I stand on in while in 4th gear (4spd Muncie)...there is this clicking..pinging sound coming from under the hood...any ideas as to what is causing it (loose exhaust manifold or exhaust pipe)?   Thanks, Lojac