Dodge 4 spd ?

I have the option to get the original 4 spd ****** that I had in my first car. It came out of a 69 roadrunner. Does anyone know what the gear ratios are? What are my options for a hydraulic clutch, or would it be better to go with a 5 spd. I like the idea of the 4 spd, but I want a driver with decent gas mileage out of my 37 truck. Is there a % of milage I would loose going from a 4 spd to a 5 spd? I could handle 1 to 2 miles to the gallon, but not much more.

 

If it is a A 833 here are the gear ratios
A-833 Transmission Gear Ratios 1st 2nd 3rd 4th

6-cyl (also 64-65 273, 74-75 318) 3.09 1.92 1.40 1.00

Fine-spline V8 (most pre-1971) 2.66 1.91 1.39 1.00

Co****-spline V8 (1966-70) 2.65 1.93 1.39 1.00

Co****-spline V8 (1971-74) 2.44 1.77 1.34 1.00

Road Race T/A; most 1971-74 fine spline 2.47 1.77 1.34 1.00

Overdrive (mid-1970s and newer) 3.09 1.67 1.00 0.73

Original is at Chrysler A-833 four speed manual transmissions — history, tech, and swap http://www.allpar.com/mopar/transmissions/four-speed-manual.html#ixzz2i4l2IxOt

 

The transmission won't know if there is a hydraulic clutch or mechanical clutch linkage. The 1st gen Dakota and most late 80s/early 90s Dodge trucks had hydraulic clutches with a clutch master cylinder on the firewall and a slave cylinder activating the clutch fork. That way you can use nearly everything from the road runner.
The overdrive will cut engine rpm about 25% at a given speed with the same tires and rear end gear. The 4 speed over drive from the 70s is a basic 833 with linkage changed between 3rd & 4th gears and 3rd being replaced with the OD gear. A 5 speed has a little better gear spacing then the 4 speed OD has, but if the motor has enough power, that won't matter.
Ultimately, there is more to gas mileage then just engine rpm. Motor build, rear gearing, driver input, car shape and other factors all have an effect on gas mileage.

My 48 Plymouth coupe has a V6, 5 speed with 3:55 rear gears, and 235x 78x15 tires. If I drive sensibly, it can get 20 mpg. It will loose 5mph pulling a long steep hill in OD(5th). The more I beat on it, the worst it gets for mileage. It can get rubber in 2nd gear with a sure grip rear end, the car is fun to drive. I consistently get around 17 mpg per tank full (this is real actual mileage). I doubt the OD 4 speed would be much different, but the straight 4 speed would net me worse mileage, probably in the 13 mpg range. With the straight 4 speed it wouldn't have 3:55 rear gears and probably wouldn't be as much fun to drive. I have the 5 speed because I had it when the car got built. Gene

 

The mileage gain with a 5 or 6 speed stick is only on the highway when it's in the OD gears. If you do most of your driving in town it wont be any more economical than the 4 speed. But if you drive the highways mostly, you'll gain about 25-30% increase on highway mileage.

 

got 3 big block mopars with 4 speeds never even worried about gas millage or going to a 5 speed

 

Gas mileage is not my main concern, but it is one. If I read this right, I can bolt my ****** to a Dodge Dakota bell housing, and use all of the Dakota stuff.