I have a 97 Marine Trader 34DC with the same engine and burn about 1.2 gallons/hour at 6 knots. Depends on transmission and prop as well as bottom condition. I usually cruise at 7 knots on open lakes and burn about 1.8 gal/hr. Not sure if yours will be the same, but probably close.
God hates a coward,,of course he's not fond of fools,either!