engine has sound of chain

[toaster13]

i recently (this past christmas) finally swapped my auto trans to a manual one. My engine has been steadily sounding worse and worse. It started this before we did the swap. it sounds like a chain is dragging, and it only does it while driving, cause i can rev the engine and it sounds fine, but while driving it justs sounds weird.
if anyone has had this problem or can tell me what it is i would greatly appreciate it. Thanks adam