Hi, I wanted to know if i could reuse the gm multilayer head gasket even tho it has been torqued down or do i need to buy another one? I'm asking because i did a head swap and now it's leaking coolant. The driver side headers thats attached to the catalytic was leaking coolant in between the header and the catalytic gasket. i'm thinking i ended up attaching it the wrong way where one of the coolant passage port blocked and the other side open.Stupid of me I must of switched them the other way around.

 

You need a new gasket.

 

Agreed. Dont even mess around. Anytime you compromise the gasket (take the head off or mess with it too much) You need a new gasket, make sure to resurface the head using one of those nice air tools

 

technically you CAN reuse a MLS gasket, but I would just go ahead and buy the new ones for piece of mind. I had graphite gaskets when I took my heads off, and I went ahead and just bought another set of GM graphite gaskets.