I picked-up DD2003 and it is more accurate. When I get a chance I will rerun the combos and add some flat tappet cams.
The 96 roller cam is actually pretty good.
Here are some Desktop Dyno 2000 Runs with the same engine, a 351W, GT40 heads, small tube headers, same intake flow and SEFI fuel injection. Note that DD2000 is optimistic by about 13%, so 400ftlbs becomes 348. Note that there is little improvement over the stock 96 roller cam and that horsepower improvement for the comp 35-312-8 and HO are gained up high in the RPM range but some HP and much torque is sacrificed on the low end. Also note that all of these cams allow the engine to run with your stock computer with MAF. There is some confusion in prior threads I have read. Yes, the HO or Comps 35-312-8 would be an improvement from a stock flat tappet cam, but wouldn't be my choice for a roller cam to get these big heavy rigs moving. Where do you want the power, lower end or higher end? It seems to me that lower effective gearing, taking in to account tire size, than stock gearing and a higher stall torque converter might favor the higher rpm cams. that's common in Mustangs but not our rigs.
Bigger heads, headers with free flowing exhaust, and aftermarket intake could very well require bigger - injectors, MAF, throttle body and tune to get the most out of it. You need to fuel it properly for the power your making. A 19lb injector will support 250 horses at an 80% duty cycle. You are pushing it too much beyond that and that is another reason I prefer the cams that produce more torque down low. At 305HP you are maxing-out the injectors. As you can see below, several cams do that as shown below, but these power numbers are overestimated for these builds in DD2000.
I also think many have gotten away with maxing-out the injectors because it is only for a short time when hitting the higher RPMs and I believe the injector calcs to be conservative.
Ford F4TE (stock 96 roller cam):
Crane HR-220 332-2S2-14: