this is true Rumble a lot to be gained here but my test @273 CFM was done with only the pinch area polished and these numbers are unattainable by a chevy casting of the same vintage. with the pinch cut out *** much as posible without any mods i have gotten 280 CFM these are very similar numbers to other members that have done there own testing and it would take major surgical work to make a chevy make this kind of number. (I didnt get the idea you were arguing the comparison with chevy,its stated for other readers)
This is also true. I have 2 points to make here first the video would lead some people to believe that the exhaust port is so good there is no need for a header, If your goal is to get what you can out of factory pieces good exhaust ports does not leave you a choice here HEADER will always make better power across the board. So the mention is made cause the mopar needs more help in this area. The second point witch the vid states is small block really react to simple mods. Part of the reason here is because of the poor exhaust port, with a good intake and out of balance exhaust like a J casting the header do more the moving the exhaust helps the balance witch make a larger difference because it allows the intake to do more work. Dyno test can prove it. Some one stated in a comment on the vid that he was right cause he had was talking to a old school engine builder and he stated work exhaust first cause if you cant get it out the you cant get it in...I work the other way if you cant get it in witch is what the engine is using to make power then there is nothing to get out. BUT there must be a acceptable balance and SBM does that.
