pipe popping

finally got the time to dig into this issue and was hoping to find an answer but not sure. Definitely number 7 causing the popping. All cyls exhaust temp within a hundred degrees or so. Popping still fades away when thoroughly warmed up. So...

Off come the Dougs headers(jeez). Was really hoping to find a crack at #7 pipe and did not. All I found was a leak at the collector, which I'm not sure would cause the "venturi" effect popping noise. Could not hear or feel the leak when the thing was running. The header gaskets came off in pieces, of course. Don't THINK there was an issue there.

Here's my question to you guys:

Before I button this thing all together again, should I pull the heads and have them checked since access is there now(headers off)?

As most of you guys thought, I still feel it was an exhaust leak. I can't believe the Indy RHS heads, Ferrea valves.....all done by Brian....could have an issue with only 3000 miles.......and go away after it warms up.

What say you, guys? Pull the heads or throw on my new TTI's and run it.

Really appreciate all the help.