Junkyard 5.9L Magnum + Edelbrock LA heads build

nm9stheham said

There is the Mr Gasket 1121G at .028" thick. Not sure how it will hold under boost.... some have noted them not holding as well.... I dunno all the circumstances in their application in those cases however, like: were the decks and head surfaces true, and were the head bolts re-torqued after a few heat cycles?

I've used similar composition gaskets to the 1121G's in my 2.6L Mitsu with 14-15 psi boost for rally use and not had any issues ever...... I take that back: 1 did fail once in a rally, but the head had warped a bit.

Putting a thin coat of KopperKote on would not be a bad idea IHMO.

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So do you think my machinist could be recommending Cometics just because he wants to make sure my engine won't fail and possibly create an issue for him? I know he also mostly deals with Chevies (big blocks and LS builds) are they more sensitive to head gasket type? Then again 1500 HP builds are a daily thing at that shop so my "little" sub-500 HP SBM might be something he's not used to. From what I've read on here over the years it seems like people don't step up to MLS gaskets unless they're building something pretty hairy.

I'm also going to be running head studs so I think that would reduce the chances of a "cheaper" gasket failing even more...? BTW was your 2.6L Mitsu an Aluminum-headed engine?