Intake Manifold Heat Shield Rivets

[Gary AAR]

I am cleaning up my 340 Six Pack intake manifold, and I have questions about the heat shield on the underside of the manifold. 
Should I remove the heat shield to clean underneath it?
Whats the easiest way to remove the rivets that hold the heat shield to the manifold?
Should I replace the the rivets when reinstalling the heat shield?
Is there a source for new rivets?
Thanks for the help.

[Burdar]

I would leave it alone.  There shouldn't be anything under there.  If you have a bunch of carbon sticking out from under the plate, then you have a cracked manifold.  My original manifold had big mass of carbon coming out from under the plate.  The plate was bent from the carbon pushing on it.  I found out later that the manifold had a crack in it that ran through the exhaust crossover.

[Chryco Psycho]

There can be carbon under there the oil can Coke against the hot manifold which is why the shield is there , the rivits are twisted you can pry them out & tap them back in , it would not hurt to use locktite or you can leave it alone . A friend glass beaded his intake , all of the glass bead never was cleaned out properly & glass bead kept sticking the oil pressure bypass open so make sure you remove the plate if you glass bead !!

[1 Wild R/T]

If the motor ran Pennzoil or Quaker State it's common to have a lot of sludge in there... Modern engines or engines in general with modern oil tend to stay clean, back in the 60's & 70's severe sludge was pretty common...

The plate is easy to remove, a chisel to the side of the rivet head & normally the rivets pop right out... They are available new, they are called drive rivets...
https://www.mcmaster.com/90081a310  $8.56 for a pack of 100....   I put a dab of Locktite Stud & Bearing Mount on them when I reinstall them...

[RUNCHARGER]

You can vise grip them out as well.

[Gary AAR]

Thanks all for the input.  I was able to remove the rivets with no problem.  Now ready for more cleaning.
Thanks again.

[aussiemark]

Was there much carbon in there?

[Gary AAR]

Not as much carbon build up as I thought there might be, but I still want to get it all cleaned off.  Anybody found a good way to clean the carbon off???

[Chryco Psycho]

Glass bead !!

[1 Wild R/T]

If it's truly carbon as Burdar mentioned check your crossover... It should be cooked oil residue... Which Castrol Super Clean will melt....