I have a large number of builds using the PKelley calculator, but zero with the Wallace. If you put your information up on the build I will run it through, but results can be very different, so I can't comment on your combo.
For instance, Pipemax calls DCR on my 489 9.52:1 and hits cranking compression ratio spot on, same with my 445 but puts DCR at 9.19. Its a respected calculator and, and both engines run on pump gas. PKElley's calls the 489 8.33:1 and the 445 8.10:1. The engine doesn't know what the calculator assigns, but repeated use of one tool can give info when comparing one output to others. If I compare numbers from different calculators, it's not applicable, or at least it may not be
For laughs, I just went through and ran my 445 and 489 numbers on Wallace and my 10:1 445 came up at 7.86:1, 3% lower, my 489 came up at 7.98, 4% lower. So you aren't far off, even at 4% you'd be at 8.18:1, right at the edge of a heavy vehicle, if tuned well, but that's a big sloppy WAG