Chevy lug nuts to plug stock exhaust manifold holes?

I've got an '87 B2000. I've got a weber on and I'm just trying to remove all of the pipes that lead to the old air filter assembly. I heard somewhere on this site that a person could plug the holes on the stock exhaust manifold with old chevy lug nuts. does anyone know what chevy model and year would have the right ones? wouldn't they need to be threaded metric?

thanks in advance.

Old Russ- D knows! He is the master of this "Mod"

lol

I beleive it's just any 6 lug chevy from the 80-90's with acron/ capped style nuts- they have to have the cap to keep the exhaust in!

And they are chrome too man!

what he said, you would think that everything on these trucks is metric, but that isn't always the case.....