318 head gaskets and water jacket holes

solracmopar said

To be honest I never tested compression before taking off the stock heads. My machine shop did the milling, cut back valves, port matched intake/exhaust and milled the intake itself so that it fit right with the heads.

I just got off the phone with Summit and they are saying these head gaskets are too big for a stock bore. Any ideas? http://www.summitracing.com/parts/mrg-1121g/media/images

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I just did some similar work. Mine only were milled .015 and I used the Mr Gasket 1121G head gaskets, about $20 a pop. I had pretty good water leakage from the heads until the car warmed up a bit (I was breaking in a new cam at the time, presumably the leak fixed itself once the gaskets were heated and the teflon stuff or whatever comes on them sealed up). I put thread sealant on all the intake bolts as this engine will leak coolant and oil up thru the bolt threads if you don't. I put sealant on the exhaust bolts and either end of the drivers side but forgot to on the passenger. I think I have a small drip on that side, probably those stupid exhaust bolts.

Anyway, all that with stock pistons my compression calculates to about 8.6.