With blower motors (roots 14-71) is there a huge benefit to the latest and greatest heads. Ie new brad ta1x or new noonan/MBE stuff versus older stuff like brad 5 or 6'? Or is that just what makes the motor a few hundreds of a second better than others and really its all blower? tune ? cam ? How about ideal bore stroke ? 4.5 bore small stroke ideal ? any other comments feel free to add thoughts.