Yeah it was the 4.7L in 08 and the 5.7L in 09. Tuning changes year and year however, normally for driveability updates; sometimes there are TSB's that address certain changes that are recommended. The factory 05 tune, if never updated due to service or a TSB, is likely different than 07 factory tunes. That would explain why you feel a notable difference and we don't notice much in our 07s.