i have an '85 blazer full size with a 350 motor 4 barrel, 350 tranny that i keep around to pull the boat and carry the canoe. i was considering trading the intake and carb for a 2 barrel carb/intake to save on gas. it gets good mileage for what it is, the motor i replaced a few years back new and it only has about 20,000 on it. when im on the highway i can actually watch the gas guage moving lol. does it make much of a difference with a 2 barrel?