I had to change the input shaft seal on mine. mine has 2.73 gears and it is a little low numerically. i have the same tires as yours. i have driven it to Kansas City twice and i average over 20 mpg but around town i only get between 12-14 mpg but i does well in traffic.

Ron, The Computer Greek
I love therefore I am.
1954 3100 Chevy truck
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2017 Buick Encore
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1960 MGA Roadster Sold 7/18/2017