Technical 1946 Ford Pickup Rear End Questions

I have a 1946 Ford Pickup with a straight six in it. I have purchased a Flathead V-8 and Trans (239 cid). In order to be able to drive at our highway speeds (approx. 70 mph) do I need to change the stock rear end? Or is there a kit available to change the gears in the stock rear end? Thanks in advance!!

 

That stock rear axle is kinda rare . It’s banjo with open drive shaft .

 

I know I'm going to get a lot of flack for my answer but if you intend to safely keep up with today's traffic, your truck is going to need much more than different rear-end gears, you need to update everything suspension wise.

 

That kind of rare stock axle is also good trading material to swap with guys who want an open drive banjo rear end under their early rod.
.I'm getting conflicting info on the width of a 46 pickup banjo rear though.
Best thing is to measure your wheel mount surface to wheel mount surface yourself and check to see how close you come to The early F 100 nine inch rear.
Search shows that the 1966-1977 Bronco 58 inches 57/61 F 100 is 61.25 Those have 5 on 5-1/2 bolt pattern and the drop out third member lets you swap to what ever gears you want pretty easily.

 

I had a 47 years ago swapped in a Dana 44 from a mail Jeep , easy swap best as I recall . Also had a 48 F1 , a 66 F100 “ Direct “ bolt in . I mean do nothing and it fits as if made for it . Im sure F100 housings same up into early 80s . I think your 46 probably has 4.27 gearing . Don’t let the 46/47 rear go to junk , it’s $$$ to early builder that wants open drive shaft . To me they are not strong enough for modern driveline , but damn the look as nice as Dolly’s tits . If changing to later model , Explorer or Ranger is where my money would go .You might want to think about chucking those truck rear springs also , they are a bit much for a cruiser . But as noted they are not 5 on 5.5 bolt pattern as your truck currently is .

 

Thanks for the responses! I am leaning towards keeping the 5 bolt pattern as I don't want to lose a lot of the truck's character. The stock rear axle will definitely not go to waste...I will find a happy new owner for it. I will do some measuring and research before making a final decisions. I always like to ask the experts before diving in!!
Thanks again!!

 

Look on the bottom center rib for ratio numbers.And it will work fine behind your flathead.

 

I recently picked up a ‘46 truck chassis, just for the open drive banjo. I was surprised to find 3.54:1 gears in it.


Sent from my iPhone using The H.A.M.B. mobile app