I never got accurate results from any version of DD by using honest inputs. You have to try a lot of known builds to learn how to lie to each version of DD.
That's a way wrong cam for the rest of your combo, and if you installed it dot-to-dot, then remember that it has 5 degrees of advance ground into it. If you installed a cheap timing chain, then the chain will stretch, badly.
If that's the sort of cam you want, then at least mill the heads 0.030" to get the compression up to 8.5:1
Your combo as typed says stock low-performance heads with 1.94 / 1.60" valves. Hate to tell you, but as GM never offered that combo of valve sizes, then the heads aren't stock.
Still, assuming you built this engine this way, you should have maybe 275 HP peaking around 5000 RPM, and maybe 325 ft-lbs around 3500 RPM.
What sorts of results were you hoping for, anyway?