Hey, I have an engine simulation program by Lotus Engineering. But I've never seen it for sale anywhere. It is ment to be used by EOMs and I got a license via my employer.
With the program you 'build' a model of the engine and it will calculate the performance based on how much air is drawn into the engine. You have to exactly program the dimension and shape of parts like the inlet manifold and it will based on that calculate the flow resistance of the system. so no need to know all the cfm's.
I did some simulations on a 270 GMC engine (which has siamese ports as well) and it worked out quite well. I 'build' the stock engine with the data I had available and corrected the simulation to the know performance curves. Then I 'mounted' tuning parts to see what they would bring in hp.
I could do the simulation for you. the only thing is that I would need a LOT of data from your engine. You may even need to take stuff apart to measure all the diameters, volumes, curves etc. Is your engine stock? and do you have a performance curve to check the 'base' engine's simulation results?
