High speed rear end: manual vs. overdrive

JasonNC
JasonNC Expert Adviser
I have installed a 307 rear end from a 1953 Hornet in my 49 Super Six. It has an overdrive transmission in it, but I also have a spare manual transmission that I've been told might be a better option if I plan to drive a lot in the nearby mountains.  I'm not even sure if the overdrive transmission even works properly but I know the manual one is ok.  Any comments pro or con will be appreciated.  

Comments

  • Ric West IN
    Ric West IN Senior Contributor
    You are not going to be happy with that axle and an overdrive.  If you like working that hard, I would switch out the O.D. and install standard trans.   Then sell the O.D. to pay yourself for some of your time and labor.

    "Ric"
  • Geoff
    Geoff Senior Contributor
    The analogy of a bicycle is the best way to describe.   Ever tried riding your bike into a headwind in the highest gear?  You are working much harder and cannot maintain speed.  Listen to what Ken says.
  • Yeah, but downhill with a strong tailwind is really cool!
  • Geoff
    Geoff Senior Contributor
    Helps if you have had a feed of baked beans with onions
  • I have the Hudson 3.78 or 3.58 (out of a '51) coupled with overdrive and 7X engine in my Hollywood.  In overdrive my power band starts at 70MPH and I can easily run 80 and 85 without even breathing on the accelerator.  My opinion is the 3.07 is way too tall for overdrive.
  • JasonNC
    JasonNC Expert Adviser
    Great.  I wish I had posted this discussion before I had that 3:07 rebuilt.  I wonder if it will fit on my 54 Kaiser which is an automatic.  Even if it's the same Dana rear end, at least it is new.  
  • Uncle Josh
    Uncle Josh Senior Contributor
    Kinda makes a difference what the terrain is too.  Up here in the Adirondack mountains, you don't want anything taller than a 4.56 with the OD.  And it's still only running 2200 plus or minus on the open road where it's flat and still giving 19 mpg