Hi-po exhaust manifolds

str12-340 said
yeah, you can leave the conical washers off the center port bolts, but at $500-800 for a pair of these, I sure wouldn't risk busting the ears off of my manifolds in the name of what is supposed to be "correct".

Good point. There's no way to get cone washers under the sleeve nuts, but it might not be a bad idea to put them under the four center bolts.