Mitchell in 46-48 car
 

If you have a Mitchell overdrive in a 46-48 car, are you using the 26.6% or the 36.6% unit? What is your differential ratio? (mine is 3:78) What do you recommend? Anyone know what the overdrive ratio of a Columbia is?
Thanks, Steve

Re: Mitchell in 46-48 car
 

I have a 36% cable shift unit in my 47 with 3:78's. I live in NJ and it's pretty flat, also my flathead has a small cam, aluminum heads, and dual carbs. I'm very happy with it. I figured if I'm spending the money I wanted the biggest overdrive %. I had to notch the floor under the back seat otherwise it hit on bumps.

Re: Mitchell in 46-48 car
 

My OD is a 30% reduction type. My rear end is a stock 3:78. On the highway, it allows me to run in the 60-70 mph range. It can't be used in town because it lugs the engine too much. I shift it with a cable used for truck PTO, placing the knob under the left side of the dash. I had to make the bracket to hold the end of the cable where it joins the overdrive unit. If I had it to do over, I would have preferred a slightly less reduction ratio. If you plan to run at today's highway speeds, be sure your brakes and suspension are in top shape. I added a third stop light for safety.