Max overbore for LA 340 block? .060" too much??

I run .060 over when I can, but going larger can get pricey for custom (larger thann .030 over on the 4.04 bore) pistons. You have to sonic test. I have yet to find a block I would feel good about going beyond .060. Besides, boring on its own does not gaurantee more power. As far as the head gaskets... On a small mopar, until you reach above 12.5:1, you should not need anything fancy. Mopars do suffer from detonation especially with the factory heads and it' usually this that pops the head gaskes. That and really poor block machining from the factory that isnt corrected during the rebuild/build.