I have done some testing so far a few different ways. I put an OCP EFI intake on a 2005 Chrysler 300 where I did loose some torque which I did expect due to the shorter runners but it pretty much ran right with the stock plastic 5.7L car intake. The car has been together for a few months now and gets a best of 23.5mph. There is no noticeable drop in power whatsoever. One thing that is noticeable right away is the throttle response between the OCP and stock. I also installed one on my 68 cuda, carbureted with a built, stock cube 5.7L Hemi with ported early 5.7L heads. There is more than just a design that makes an intake manifold, it has a lot to do with drivability, application, and package. Due to the 14-15" length of a tuned runner and the EFI there are a lot of advantages due to sonic supercharging and the fact that the EFI is force feeding the correct amount of fuel directly into the cylinders. Now take the same intake and adapt it for a carburetor. Now you have an excellent EFI intake but a horrible carbureted intake that has poor fuel distribution, puddling issues, and horrible throttle response due to the gigantic plenum. In general it would be a nightmare!! A lot of things must be taken in consideration for design. Drivability (very hard to measure) Application, Carb 4150 is a standard, EFI Must be compatible with multiple EFI systems and the runners need to be the same volume and length to eliminate fuel distribution issues. Height, Cant be too tall. Downdraft due to dual purpose Carb or EFI. The runner volume cant be too large or too small. The best we could do is 7" for runner length and it had to be in a dual plane configuration in order to get that number and keep the height down. What you use depends on your choice and application. It was not designed to out perform a Ritter DP but it will fit in places where it wont. Please click on this link for a vid of my 11.26@120.1mph run >>> Cuda 11.2@120 I will dig up the dyno sheet and post it up tonight.