Motor noise from front??? (kinda long)

[meansting04]

Well the other day i was setting in a new dist. and doing timming and i notice a pretty loud noise from the front of the motor. I got a pipe and listened on the valve covers, oilpan, and intake and can not hear it. I put the pipe on the timing chain cover and i can hear it perfectly. So is my chain bad? Could it be the fuel pump push rod? The noise is not realy rythmic, and doesn't get louder or quiter with rpm. It just stays the same until the mufflers drowned it out. Motor doesn't leak so i really don't want to pull the cover it don't have to. Was running fine for about a year now, just started out of the blue. Timing holds steady at 10 deg. intial and advances smoth. The cam is not a roller. Its almost like something is hitting the front cover but you can't feel it with your hand on the cover. Any ideas??? Its on a 355 sbc with around 10k or less on the motor. Oil press is good 55 pis and idle and it doesn't get above 170 deg. Power is still good and its starts fine, runs, and drives great.