J head question

[Doobiemon]

I am installing a set of 1972 j heads, casting #"s 3418915 on a rebuilt 1976 360 Bottom end with the stock dish pistons. Can any one tell me how may cc's these chambers are. Also, what kind of compression ratio will I have. The heads have been milled .020, and I am using Fel-pro performance head gaskets, .039 thick I believe.

[Stoga]

I can't remember the spec off the top of my head for 360 heads that year, but I heartily suggest you get the combustion chambers in the head, cc'd. Due to the heads being milled, plus however much the valves and seats were ground, it can change the volume of the combustion chamber by a significant amount. Be sure to use just a little grease around each valve seat and the plug threads, just so you won't get any seepage while measuring. I used to use a 100 CC burette, with just ordinary tap water, the water won't hurt a thing, for all the longer it's going to be on there. Just clean the head and parts good afterward, maybe give it a shot of spray lube. Seriously though, if you don't measure, you'll just be guessing.

[rumblefish360]

In addition, how far down the hole is the piston and how many cc's is the dish?
Very important.