well u could wait till it gets dark and then watch on that side while its running. rev it up a couple times and see if u can see light coming out any where. it should show on the backside of the rev. the gasket/connection at the end of the headers is the collector.

 

oh ok yeah everything seemed fine down there but then maybe the dent was caused by bottoming out and it messed up the gasket... im confused because it doesnt do it while in park but in any gear it will knock slightly and when you accelerate it just sounds terrible its real bad when accelerating... its embarrassing

 

can u get a recording of it so we can hear it. that would be a big help. both an exhaust leak and a mechanical problem can make this noise but there is a small difference to them. lifter should come from the valve cover, rod knocking will come from lower down but more towards the oil pan. out of curiosity does it back fire just a little when letting off the gas?

 

Here is what bolts onto the header collectors, and the exhaust connects to it: http://www.summitracing.com/parts/HED-21111/
There is a gasket between the colector and reducer rings. Make sure those gaskets aren't leaking, and that the bolts are tight. If they are leaking, you'll be able to see black soot between the rings.

 

Ill get a recording right now... its just back pressure but not actually back fire like a liud bang... just a muffled pressure sound, I do have a small oil leak coming from somewhere though Im not sure if its the oil pan gasket but yeah I dont think that would be causing it, ill get a recording and post it here

 

from the way u explain it, it sure sounds like an exhaust leak. do u have catyletic converter/s? if so how old? have u checked the connection at the collector like 69 said. sound can carry threw the pipes or bounce and seem like they are commin from somewhere else.

 

Piping looks fine and bolted... however the guy who had it previously had it sitting for like 10 months so who knows what happened to them... here are the recordings:

In park: none to minimal noise
http://img190.imageshack.us/i/dscf6739.mp4/

While Driving:
http://img190.imageshack.us/i/dscf6741.mp4/

 

No black soot there

 

that sounds like an exhaust leak to me. if u can get someone to rev the motor up and down so it does the little backfire thing while u look for light or flames coming out of the exhaust. should be able to listen your way to a close area of it. then look for the light from the little backfire. if u cant see the light, lol, use your hand to feel for the exhaust comeing out, do it where u can i understand that some places u just dont put your hands or they get chewed up or burnt.

 

yeah sounds reasonable... so it shouldnt be a lifter or rod right? because if it was then it be doing it at idle as well right?