The main problem with any of those programs is they only offer modern cylinder head port and chamber configurations. This is fine if your doing a simulation for a SBC or BBC or any IR runner style head. But it is almost useless when trying to use it for a siamese port head because there is no direct comparison between this type of port to any other port selection to chose from in those software packages. Also, it is nearly the same when constructing a Flathead style port or chamber vs. the modern OHV layout the software is designed to use. So if your intention is to use it for older vintage engines that have siamese ports or L-Head style heads none of the software packages will give you any realistic ideas of any gains or losses and would be a waste of money to invest in. That software just isn't designed around those types of engines or parameters.
