As I cleaned up the individual header flanges, I noted that all three primaries lead into a chamber before they exit out to the turbos. If you look close, there are gobs of weld material at the 1,3, and 10 o'clock position. In addition, there seems to be too much weld material all around. I took a grinder to the weld until it was perfectly round and smooth. This is sort of like removing a booger from deep inside your nose...though small/thin, you can breath easier!!

the second picture you can see how I got aggressive. Hope it will stand up to the heat/time...will post if any problems.

 

I've never picked a booger out my nose so wouldn't know what you're talking about....ahem.
Would you mind taking an after pic from the same view as the first one? Not sure I'm seeing what you did. Sounds good tho. Good luck with it.

 

If you look at the flat collector inside, make sure that you don't have a primary tube over-lapping into another tube. You can trim away the tubing. Please take the utmost care to get all of the metal debris out of the headers/heat exchangers.

You need to make sure not to grind all the weld away. You don't want the flange seperating from the collector..

 

Acropora, notice on the first photo how the black inner welding is not round against the background white exhaust...especially on the upper half. From 9 o'clock to 3 o'clock, on the most black part against the background pale white you can see how its very uneven. Lumpy. this is what I ground down until smooth and more round.

Jaime

ps. notice the red pipe wrench my daughter is holding....this is the best/fastest way to remove old exhaust studs if you are going to renew them. Make sure you apply your favorite nuts loosener and grab stud close to the base.

Jaime