i've got a similar program that costs about 500 bucks that involves much more than DD, i used to use DD until i discovered the better software, i'll run the numbers when i get home.
i need to know your thermostat temp, water pump design and fan setup.
what size are the primaries on the headers, and what specific intake manifold is on it? also, give me the size of the air filter, it will give me back hordes of information.
it will tell me where to set the timing, likelihood of knock, holley jet sizes, BSFC etc. i've had VERY good luck with this program. extremely realistic.
PS, are they vortec heads?