Slow loud metal clank

[thenextmoneypit]

4.3 6cyl seems to be coming fr

4.3 6cyl seems to be coming from top end near carb.Its loud like a metal 2 metal hammering clank.....clank.....clank..etc It doesnt speed up when revved just hits louder. any Ideas? motor is beleived to have a cracked head
thanks
Adam

 

[thenextmoneypit]

The sound went away after abou

The sound went away after about 15 Secs.
new prob in other post.