2005
Chevy Silverado 1500
5.3L Engine
Automatic Transmission
4x4 Transfer Case

Ok, so I'm gonna be replacing head gaskets on an LS engine and have a couple questions.

1) That aerosol copper spray stuff for head gaskets.....does it add any benefit. I've never used the stuff. To me, it seems like a gimmick.........for a company to make a few bucks........kinda like all those bottled chemicals that are supposed to "repair" your vehicle.

2) Torque sequence.........The head bolts are the Torque To Yield design. First pass is 22ft Lbs, then all remaining passes are measured in degrees of rotation. Anyhow, that first pass of 22ft Lbs.....after that one pass, those center head bolts are gonna have less torque than 22ft Lbs because the rest of the gasket is getting compressed more and more with each torqued head bolt. Wouldn't it be better to make how-ever many passes @ 22ft Lbs to ensure that all head bolts are infact 22ft Lbs.

So, do engine builders make multiple passes to attain equal torque for every head bolt before proceeding to the next sequence.