Engine How common are blown head gaskets on a stock 5.0?

Last I knew the red stuff was used in GM vehicles with some "pellets" to stop the water leaks caused from the plastic intake manifolds GM loved to use... My info is a few years old, but as far as I know they still do it.....
 
Last I knew the red stuff was used in GM vehicles with some "pellets" to stop the water leaks caused from the plastic intake manifolds GM loved to use... My info is a few years old, but as far as I know they still do it.....

That pellet stuff was with the Northstar engines. I rebuilt a bunch of those. Complete PITA. The GM stuff is Dexcool and it's orange. ( they still use it ). The closest OEM to red is the Toyota fluid but it's pink. I posted what it was. I know a few guys that swear by it in their race cars. It doesn't corrode, break down, or cause electrolysis like regular antifreeze. I've never used it personally. I did use Toyota fluid in one of my mustangs because of its self sealing properties. The gaskets never leaked. I wouldn't recommend it or do it to anyone else's car though.
 
Did you ever find a solution to this issue? I am having the same issue with my 1995 Mustang Gt 302, installed a new upper / lower intake and a new 3 core radiator and ever since I have been having pressure and bubbles in my coolant system that I cannot bleed out. When I drive it I get the same "old Faithful" overflow of my expansion reservoir. I have also torn down my heads and the gaskets appear fine and I see no cracks in the cylinder or combustion chamber of the head. hoping you found a solution to this since December.