Lots of great info, thanks everyone for taking the time. At least it gives me a list of questions for the long block supplier when I get to choosing the remanufactured long block to use with my Gibson headers. I know the larger throttle bodies for the 2008 and later 4.7V8 probably really help the engine breathing the most in the 4,000 rpm and higher revs. Perhaps the older slightly smaller throttle body still works as a smaller bore TB means the air velocity would be higher especially for the low to mid rev range of the engine. Generally, the higher airflow velocity at lower revs means the torque curve shifts to the lower revs. More research required.