i have 2 1440 IHs one is a 79 and an 84 the newer one will run 1 mph faster in any crop than the 79 i dont know the difference it must be in the pumpIJ 84 runs about 2750 when in use and 79 about 2650. if anyone knows why i would like to know 79 has already been "turned up" one turn on the screw. both are 135 hp non turboIJ