Compression ratio calculator?? And power figures?

273 how accurate is your dyno program? those are crank hp figures right? Give or take anny loss in numbers, in the real world? I know its just a guesstimate, but it just has me wondering. Swinger 340, as far as i know, the bore is 3.91, 3.31 stroke, heads are milled to 61 cc, and the pistons are .050 - .060 in the hole. The only thing i couldnt be sure on is the thickness and bore diameter of the head gaskets. Ive tried to check everywhere but only found .028 on those mopar brand gaskets. Its hard for me to remember correctly, but i think the piston was most likely.060 in the hole.