89dieselkong

I am doing a DRW to SRW conversion, changing the gear ratio from 4.10 to 3.54, and taking out the 47re and putting in a NV4500. I am assuming my MPG should increase?? Any guesses on how much??

Southern Pride

i did a auto to man swap last march. ive got a 1ton dually 4wd, with 3.54 rear gears. my mileage hasnt increased all that much, cause i keep my foot in it, but with the auto, in od/4th gear, at 70mph, i was at about 1800rpms. now at 70, im at about 2200 rpms. even though im turnin more rpms, due to the truck being a manual, and im controlling the shifts, and there isnt anymore slippage, the mileage is about the same. i average around 15-17 city/highway mileage, and about 18-19 on the highway at 75-80mph. you might get better mileage since you wont be havin the extra wheels and fenders stickin out, and ive got a ranch hand that weighs about 300lbs on the front soooooo who knows?

RowJ

Should get 20+ mpg on hwy.....so +3-4 mph. That's based on my automatic experience vs what most 5 sp, 3.54 owners report... but your the first I've read that did that much modifying.
Only mileage question would be drag from body flairs??

Better gain that much or I bet you won't be very happy?

RJ