swapping a rear end in a 1950 F1 pickup

[pickup]

I am looking for information on swapping out my Dana 41 to a Dana 44 in a 1950 Ford F-1.

The truck has the original 8BA Flathead and 3 speed transmission. The Dana 41 has a 3.92 ratio rear end. The truck has 15" wheels. At 2500 RPM. its going 50 MPH in high gear.I found out that a 1957 thru 1972 F100 rear was the right width and would work with a few problems.

I called around to many junk yards in my home state of Georgia and asked if they had a dropuot rear end for a 57 to 72 F100 and all answers were no except one. It happens to be in my home town of Peachtree City. They want $250.00. I asked what the ratio was and he said it was a 3.25. I am now unsure if the 3.25 will be too high given what some people have said. I did check my tires and they are 88" around or 28" across. I guess the 28" is the number I need to use. of course third is direct.

I would appreciate more feedback on the 3.25 ratio before I pull the trigger on the purchase. I did check on Dana 41's and no one has one either junkyard or specialty drive train house has a 3.72 gear for a Dana 41

That brings me to the other delima. I will ask the junkyard to save the spring shackle bolts and the emergency brake cables but I understand the shock perches are different. The are smaller on the Dana 41 but the quesion if I get the shock perches off the Dana 44 which is still in the truck will they work with my 1950 F1 truck? Also I have heard that the drive line on my truck will be one inch to short. If I get the drive line out of the donor truck will it work?

[Firepower flyer]

I don't have all your answers,I have the same truck as you and plan on doing the same swap.If I had to pick I think that 3.25 would be great.There are several write ups doing this swap on the Ford Truck Enthusiats (FTE) website. There may be some one here also if you use the search function.I'm still looking for a axle.Good luck keep us posted.
Joe

[waterboychuck]

In doing some research on a 9 inch Ford rear end for my coupe I came across some ratio information and wrote it down.3.73 - 4.10 are more for drag racing while 3.23 is for the street. You may want to google it.

[rotorwrench]

The Dana 44 should be a direct fit since is replaced the Dana 41 in 1950. Most 1950 models should have a Dana 44 but they were likely used after the Dana 41 was used up. You should be able to get lower ratio gears for a Dana 44 since they were used many more years than the 41 and carriers & gear sets are available for them through outfits that specialize in rear axle assemblies.

[TJ]

Check with Summit, they have gear sets that will probably work for you.

[Ken Crans]

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Welcome to Fordbarn!! Another F-1 guy..I found mine out of a 63'' F100 with a 3:54 ratio that was a direct bolt in, shock brackets on the earlys have a post for lower mount and up to 72 they had a bracket. i used a 72' 9 in in my 47' with 3:73 gears, i had to alter the lower bracket to line up with the upper. They are very plentiful.. anywheres from 150 to 400. search C L theres a ____ ton of them. Good luck

[Ross F-1]

Originally Posted by pickup

..... I did check on Dana 41's and no one has one either junkyard or specialty drive train house has a 3.72 gear for a Dana 41
...

3.73 was the standard Dana 41 ratio for 48-50 F-1's. There are hundreds if not thousands of 3.73 axles around, having been replaced with 9" rear axles. Just watch craigslist and eBay.

[49r]

In 1976 I swapped my 49 F1 Dana 41 4.27:1 diff for a Dana 44 out of a 56 F100. I'm not sure of the exact ratio of the 44, but it is either 3.92 or 3.73, according to my Kiwi manual. It was a straight swap with no modifications required - still going strong too. I understand 3.54 gears are available for the Dana 44, but not the 41.

[alanwoodieman]

I have a 41 3/4 ton truck with a stake bed, 8CM, 77b Isky cam, running a 28 tooth trans out of a car, longer second gear for traffic and I run a 3:25 9" rear end. Great cruiser, a little hard to start off on a hill, but probably because of the extra weight I am toting. I also used a 3:54 gear with it but the gears were noisy and then I tried the 3:25. I thought I would get the 3:54 repaired and put it back in, but I have gotten used to the higher gear.

[tanner]

Ken, Can't seem to open your pics but I am in process of installing a 9" rear end out of a 59 F100 into my 49 F1 and just realized today that I will need to modify the shock bracket from the 59 to line up with the upper shock mount. Your photo doesn't seem to show the modified bracket you used. I would like to get more info from you on this. Also, was your drive shaft a direct fit or did you need to modify it?

[TJ]

When I did this swap I used the shock brackets off a 48-52 Dodge pickup.

[Ross F-1]

Originally Posted by tanner

Ken, Can't seem to open your pics but I am in process of installing a 9" rear end out of a 59 F100 into my 49 F1 and just realized today that I will need to modify the shock bracket from the 59 to line up with the upper shock mount. Your photo doesn't seem to show the modified bracket you used. I would like to get more info from you on this. Also, was your drive shaft a direct fit or did you need to modify it?

I used a '70 9", cut off the lower shock brackets on that and re-welded them to align with the stock uppers. I had to use a sleeve in the lower shock bushing because the newer bracket uses a larger bolt.

My driveshaft ended up a little over an inch short. I swapped yokes on the 9" to one that is an inch deeper, has been good.

[mtflat]

With the info pickup has, it sounds like he's been over at FTE reading the articles that several of us have written.

Ross has great pics of the differences....unless he has a 3 spd HD trans - then a longer slip yoke on the driveshaft is an easier swap.

[Ross F-1]

The only reason I swapped the pinion yoke was that the diff was already apart for a rebuild. Good point, Tim!

[tanner]

Ross,
Any suggestions on donor vehicle for the longer pinion yoke or a longer slip yoke?
Thanks.

[Ross F-1]

Not sure what applications it comes from; my rebuilder thought it was used on LTD's or some other passenger car.

[robby]

4 yrs ago i used a 1970 ford 1/5 ton 9 in 3.25 in my 51 3 sp i cant burn the tires but it give me good speed at lower rpm bolted right in. use all stock parts. all i did for shock was reverse upside down drilled hole to drain water but no problems

[JSeery]

The gear ratios you select depends on what you are wanting to do. Trucks came with low gears because they were used to haul heavy loads and tow. They were work trucks. If that is how you are going to use it, those are the gears you need. If you are going to drive it on the highway and not tow or carry loads a 3:25 would be better. Just remember, it is going to put more of a load on the engine during acceleration and you will have to take it a little easier, but would be a good highway gear. That is the beauty of OD, it can be a win - win on rear axle gear selection.

[robby]

on my second 51 p u i have it got a 3 sp as well im looking into putting a 1950 mercury 3 sp od trans. i hear very little changes to be made. like trans mount and drive line
it use the same trans spacer between the block and trans same clutch hook up so i going to look into this it. i have all the parts now gota do it. i have a 3 sp on the tree with od and use the stock rear end

[pickup]

I am swapping a 52 F1 (same truck) How did the 3.73 ratio work out and exacly did u do about the shock mount on the rear end