the 380 hp motors had a revisted intake and a more importantly a 90 mm MAF housing (versus the 80 mm for the 360 hp combo). on a side note, stock 03-04 trucks make 350-355 rwhp on most dynojets right off the showroom. must be an efficient driveline

exhaust does very little powerwise on a positive displacement blower motor.

stock they run 14.1-13.9 in the heat. 13.7-13.6 in cooler air. chip, filter, pulley they can run 12.80-12.90 all day.