1970 Dodge Dart 318 upgrades
The OEM is a guess, this is the only place I have found any information about the stock cam.....
318 Engine Specifications
Looks the same as in the '68 FSM for lift and overall durations. But what has been done (by you or the program) to simulate the slow ramps to .050" lift? It won't be nearly as fast as the Voodoo or XE lift rates. I'd expect the .050" lift durations to be shorter than the total durations by somewhere in the 60-65 degree range, if not a bit more.
BTW, if you enter the numbers in a different way, the stock LSA is 109, ICL is 110, and the stock cam's ground in advance is -1 degrees (1 degree retarded).... if I computed it right.
And yes, the 703 VooDoo is not where I would tend to go anyway for the stock 318. Try the 700 or 701 level. The Comp XE you shows is very much like the 701 VooDoo, but the Voodoo's 112 LSA will make it a bit different than the Comp.
It is indeed not intuitive that the Comp would have the big torque drop off compared to the stock cam... that is the source of questions. One difference that is readily apparent is the stock cam's mildly -1 degree retarded timing relative to the Comp's ground in advance of +4 degrees. That would indeed move the torque peak lower, but not drop the torque at high RPM like is shown. That leads to ask about the model of the 318 head+intake flow. That is a big deal here; if it flattens out at at .400" lift or lower, then the higher Comp and Voodoo lifts won't do anything. That needs to be examined/explored in the modeling.