Rear end swap


   Working on a 46 pickup and would like to know what rear end one could get with ratio in mid 300's with same bolt pattern that could be made to fit. I know spring mounts will have to changed. Has stock in it now which may be 4:56 or something in dat range. Has 308 Twin H and overdrive trans and want to reduce RPM's.
    Thanks,
     Kim

Comments

  • I use 57-59 Ford full size passenger car rear ends. The spring perches are in the right place. The lug pattern is the same. The driveshaft bolts up, and they both use bendix brakes, so the E-brake cables hook up too.... The only downside is, they are a little too narrow, so require a one inch spacer between the drum and the wheel. These cost about 50-60 dollars. Your Hudson rear end is 60" wide from drum to drum. Late 40's Plymouth Satellite/ road runner/ charger are 60" and use the same lug pattern. I think Ford Granada (Mercury Monarch) is 60" wide as well., but make sure it was a V8 car, because the six cylinder cars came with four lugs. I have the late fifties Ford 9" in three of my current Hudsons and two that have moved on to other owners. I find these rear ends listed on Craigs List pretty regularly, and they are pretty popular in the hot rod and muscle car world, because they are the narrowest 9" that Ford produced, and ring and pinions from the low 2's up through the high 6's are available brand new.
  • 1st & 2nd generation Ford Explorer 8.8 rear end is 59 1/2 " wide. 1991-94 have drum brakes. '95 and up have disc brakes. Factory ratios: 2.26, 2.47, 2.73, 3.08, 3.27, 3.45, 3.55, 3.73, and 4.10:1.
  • Uncle Josh
    Uncle Josh Senior Contributor
    A 51 to early 52 Hudson automatic 3.58 gears will fit right in. 
  • Courtesy Man
    Courtesy Man Expert Adviser
    Years ago I put a Ford ( 9 inch )1971 Cougar rear end in my Hornet powered 1947 Truck - as I recall the spring perches needed relocating and I switched the 3:1 ratio pumpkin to 3:50  and would have preferred about 370:1 (about).  Had3 speed with overdrive. Drove it all through the Western states - could cruise at 80 mph but not stop very quick.  Gert
  • kamzack
    kamzack Senior Contributor
    Thank you for the help. I've learned there's a difference in width between Stepdown and pickup, if so can and how could this be overcome? Uncle indicates, if I understand correctly, the gearset or pumpkin can be swapped between the truck and stepdown gearsets. Please advise how I could proceed.
        Thanks in advance,
          Kim
  • Uncle Josh
    Uncle Josh Senior Contributor
    Well, you have to pull the axels out enough to clear the punkin gears.  Swap punkins and put the axels back in.  Yes the stepdown housings are about 5 inches narrower than the truck and anything 47 and before but the axels are different to compensate.
  • Will the punkin from a hydro 51 fit a 37 terraplane. I swapped in a Hornet and would like  to have less revs a highway speeds . 
  • Uncle Josh
    Uncle Josh Senior Contributor
    If the access plate bolts on the back of the 51 rear end it's a Spicer and the punkin will not fit the Hudson and/or Terraplane rear end.  You can switch to 6:50 16 tires and a Hudson 4:11 rear end for better gearing.
  • I put an early 70’s Mustang rear end 8 inch Ford in my 46 pickup. Measured backing plate to backing plate same as my 46 rear. Just angled the spring pads like the 46 and got new u-bolts.
    had to extend the drive shaft. 
  • Jon B
    Jon B Administrator
    Gus Souza, long-time Hudson mechanic, recommends the Chrysler Corp. 8-3/4" rear axle for Hudsons approximately 1934 through 1947.  The 8-3/4" rear axle was used by Chrysler from 1957 through 1972, in a number of cars.  The track varies from model to model, running from 55.6" through 63.0".  If anyone would like to see the technical info. that Gus has assembled on this, I'll be glad to e-mail an information sheet I put together after talking to him.  Just e-mail me at xxxdetailed@verizon.net (drop the xxx before hitting SEND).
  • kamzack
    kamzack Senior Contributor
    Thanks again.
       Kim