As hard as I try, I always have problems putting info in these online compression calculators. I always get off the wall stuff.
468
Bore 4.311
Stroke 4
Piston is 15 thousands down, We are going to check it more accurratly, but this will work for now.
Gaskety is 4.5
Pistons have 250 dome (.250
Chamber is 103cc.
If i am forgetting anything please tell me.

You need to know your dome volume and head gasket thickness. If you can't find the dome volume information from you piston maufacturer, you'll have to press the dome into some modeling clay and then cc the impression left by the dome.

Dome is .250
Gasket thickness is 0.41
gasket diameter is 4.5

I had the same problem, then I found a catalog that listed the dome in CC's (Summit). I think that .250 might be dome height, one of these guys should know for sure.

Z,

.250 is the dome height. You need to know the dome volume, measured in cc's in order to determine your compression ratio.

Chris

I think .250 is like -27cc's....at least I'm pretty sure smile.gif I have .250 domes in my 454 and thats what they are, so maybe your volume will be a tad bigger