Strange Rattle

I have a 340 in my 68 Barracuda...

I seem to have it running strong... no pinging or bogging and lots of fun to drive...

But when I am taking it easy and just driving around, there is a rattle at 1900-2400 rpms....

I am not sure where it is coming from, the motor pulls good, and makes no noise at idle or when I step on it....

Is this normal, or anyone have any suggestions or comments?

Thanks!
Author: admin