Well I can tell you that my '69 cuda 446ci at approx 10:1CR went from 11.3@118 with stock 906's to 10.7@125 with no other mods than fitting TP 2.14/1.81 906's that I bet didn't flow much more than 260cfm, and I only ran it the once before hitting it with spray, reckon it could've gone in the 10.5's with some tweaking. I did run a .650/290@.050 solid FT cam and because of that I bet nowhere near your 200psi CP, I probably would've made more power with a cam with less dur. and an earlier closing intake valve, comp is not all of the story. That would 99.9% be a Chinese made Head, those 294cfm numbers are rather happy numbers if they are OOTB, Eddys don't flow that much, probably where Jegs get their heads from. Even if they manage 275cfm its gonna make you fly.