Tractors

While troubleshooting for a problem with uneven cutting, I noticed that there is an approx 3/8" difference in elevation of the mower blades, weather I check on the pulley side or the blade side. Laying a straight edge across either the pulleys or the blades show the same thing, they appear to be parallel but not on the same plane. All bearings, mandrels, etc. appear to be in good order. Is this the way the deck is designed for a PB195H42LT?
Thanks,
Byron Wood