I have blown my 5th set of header gaskets on my sig truck. The driver side has been fine for 6 months but the passenger side blows them constantly. I put a straight edge against the flange and it checks out. Is there a specific "break in" I gotta do after installing new gaskets? Should I retorque them after the engine gets up to temp?

This was my last gasket after 4 weeks

 

Those gaskets look like junk. What brand are they? The only two I have had success with are Mr.Gasket Ultraseal and Remflex.

As for break in, no not really. However you do want to re-torque them after a few heat cycles.

 

You need better quality gaskets… Fel Pro, etc.

Try these… 460 Engines

 

If it was gaskets, why would only one side be blowing out?

 

You may have a warped header flange or cyl. head mating surface… doesn't take much. Try two gaskets…

 

Don't try two gaskets. I would go with a set of Remflex gaskets. They are extra thick and have a 50% crush built in meaning when you tighten them they fill any imperfections or warping to give a good seal.

 

From my OP

 

Checks out when it's cold maybe, but a cold engine never blew a gasket.

I have to agree those gaskets look like junk. I ain't ever tried the Remflex but if they have a 50% crush margin then I'd say that's better than using two gaskets.