Yes, Goin to a bigger gear will cause less gas milage. Because it will be running at a higher RPM. So say with your stock gears now in OD going approx 65 you will be at 1500RPM. Now with new gears going 65 in OD may cause u to be at 3000RPM
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347 Stroker Motor: Balanced, A9P Computer, Cobra Transmission, Extrude Ported and Polished Upper and ported Lower, GT40 Milled Ported and Polished Heads, B303 Cam, BBK 1 5/8 Headers, 30lb Bosch Injectors, Holley Fuel Regulator, March Underdrive Pulleys, Perma-Cool Fan, 3-Core Radiator, Accel Performance Coil, Accel 300+ Racing Wires, Ram Air, K&N Filter, 79mm Mass Air Unit, FlowMaster Exhaust w/BBK Offroad H-Pipe, Hurst Short Throw Shifter, 3:55 Gears, Ram Clutch, Cross Drilled Rotors
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