Transmission Upgrade?

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JBswth

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C25
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Talking about a 70s - 80s gasser Squarebody. A diesel will always use less fuel. And by Japanese-like mileage I am talking about 30 or more MPG in a Squarebody. Can't be done with the stock gas engine.

J. B.
 

JBswth

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That's pretty surprising, as you would think that the bed would act like a scoop and catch the air.

J.B.
 

dragstews

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Body 1954, frame 1975
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406 ci SBC
You Guys just about talked me into pulling the mouse motor (406 ci) and go to a rat motor ...

Then again I have this 12 valve sitting right close ..

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Need to do sumthin with it .. ??
 

AaronW

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I remember Mythbusters did this on two different episodes back in the day because people didn't believe the results the first time. Driving with an open tailgate gave the worst mileage, and driving with a closed tailgate gave the same mileage as having a bed cover. The open bed with a closed tailgate creates a vortex that helps air passing over the cab continue on unimpeded. Oddly enough, they got the best mileage with a net style tailgate.
I've got a flat bed, in any case.
 

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