Cometic Head Gasket
My son uses Cometic on his 4 cyl. turbo motors. He takes the rivets out and does the copper coat on all layers. He said they do that at the machine shop on certain motors. One of them is a SB Mopar and anything LQ cooled with less the 5 bolts per cylinder. He now works a HTA machine as a machinist and builder. And is learning a bunch of tricks.
They are doing another 340 for my other Duster. Pump gas street motor for a driver.
I went a little overboard on my orange Duster. I don't regret it. But its not really practical for the street . Sooner or later it will get me in trouble. When you pull up to a stop sign and its shaking around at 1500. It flash stalls a 5500. Its very hard not to launch it. Even harder not to shift second and third with 456's and bellow the Tires. It is like driving a over powered shifter cart out of control. Shifting At 8500 your not steering it you aim it with a death grip on the wheel. If I were to do it again it would be 4 spd. or a lenco.
I better stop before I need to go out and take it for a ride. There isn't nothing like a High revving SB stroked that can take constant abuse. I hope they have them in heaven.