I’m not sure if you can tell what my engine compression is for these build sheets

but if you hear heads can please let me know

I’m just curious on what it is

 

There is no information about your cylinder heads. What are you using for heads?

 

I believe they are the stock heads
the block is a 1976 455

 

You didn't provide all the info, but let's assume the following. The pistons are advertised at 18cc dish. What head gasket? I'll assume a FelPro that's 0.039" thick and 4.2" in diameter. The heads, assuming they are untouched, should be 80cc chambers. So all of the previous would give you about 9.7:1.

jerry

 

Actually you’ll have closer to 9.25:1.
A ‘76 will have J heads, which are normally 84-85cc
Next, that piston is short so you’ll have at least .030 deck clearance. Add the gasket and you’ll be much closer to 9.25:1.

 

The engine builder provided deck clearance of less than 0.010" on each cylinder. My original estimate took the deck clearance he provided into account and a 0.039" think head gasket. If the heads are 85cc and not 80, then compression ratio would go from 9.7 to 9.3:1.

jerry

 

I didn’t see the .010 deck, sorry.