i need a little 340 help. Lets Talk head gaskets

roscoes-garage said
Hello All,

I have a 340 I purchased several years ago as a short block. I was told it was 12.5:1 pistons they are .040 over. I've cleaned it and am ready to complete for my duster.
the issue is I purchased a set of the 340 Edelbrock Heads (60179) with the 65cc combustion chamber i am using .040 MLS head gaskets and the top of the piston are hitting the heads.

The combustion changer depth is 0.050 I also had a set of J heads sitting around (they need to be reworked) they are at 0.100

I know there are a lot of thickness options i have on the MLS head gaskets. Has anyone else run into this issue? the block has never been decked. (I know the full history) is there a combination that worked?

Thanks
Chad

Seems the pistons were designed/intended for open chamber cast iron heads.
I would put strips of clay on a piston, install the head with gasket you intend to use and turn it over with a wrench. When it stops without forcing, pull the head off. This will show where and about how much to have a machine shop take of the piston crown. Might be possible to set up the pistons in a lathe to cut the offending amount off.
With a 0.040" compressed gasket you probably want the piston 0.005" above the deck for strong quench and swirl.