Sorry lol not very good at copying and pasting links with my phone. So a few screen shots was the best I could do.
But I do agree that the cracks between the seats on magnum heads mean very little in the way of performance.
I'm pretty sure that with a 52mm throttle body that he might of went close to the 320hp mark stock. But everyone gives up on the fuel injection then slaps a carb on. The 5.9 dakotas and rams have been repeatedly dynoed at around 320 with a tune, long tubes and 52mm throttle body.and the track numbers backed it up