Thread: Fuel economy of 7.4L (454) powered 3/4 ton suburban
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Old 03-30-2015, 02:22 PM   #23 (permalink)
cosmick
Experienced UAW Mechanic
 
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The 7561 is an RPM AirGap, probably the worst thing for MPG short of a single-plane. The younger guys call it a fail.
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