doogan Posted February 19, 2018 Report Share Posted February 19, 2018 I have been searching for a 3.73 or similar rear end for my 49 B1B. I located a 48 Desoto complete rear (hub to hub) the guy says two revs of drive shaft to 1 drum rotation?? He says he has looked over the housing and sees no notation of ratio on it. In addition he has the original engine saying its a 250 cu in. It is located a day away so I would like to know if it would work in my truck before heading that way. 1. Will the complete rear end fit under the truck or would the ring and pinion fit in my original rear housing? 2. I have read I think, that these engines were a bit longer than my 218 and to use it would need to shift radiator forward. Is that correct? 3. It has a fluid drive transmission as well. Does that make a difference in how these could be adapted to the pickup? 4. Would the engine and rear be worth swapping out in my truck? Thanks in advance guys Don Quote Link to comment Share on other sites More sharing options...
doogan Posted February 19, 2018 Author Report Share Posted February 19, 2018 Sorry guys I'm not sure how 3 of these got posted other than I spent too much time on the submit button! Quote Link to comment Share on other sites More sharing options...
The Oil Soup Posted February 19, 2018 Report Share Posted February 19, 2018 A common swap is an 8.25 rear from a jeep Cherokee. I put a 3.55 out of a '93 with drum brakes on mine, weld on new spring plates and was good to go. The drive shaft even bolted right up with no mods. The new axle is about 1.5" narrower than stock. Quote Link to comment Share on other sites More sharing options...
jmooner3 Posted February 19, 2018 Report Share Posted February 19, 2018 I don't know about the rear end but when I got my truck it had a 236 Desoto in it (Seized). As you stated it was a 25" block vs what was originally a 23" block. The PO had cut the radiator supports and mounted it a couple inches forward and made some box steel motor mounts for the front. If it's from a car you may have to swap the oil sump and pan around. As Truck and cars are different. Quote Link to comment Share on other sites More sharing options...
Iowaboy Posted February 21, 2018 Report Share Posted February 21, 2018 So I didn’t see an answer to your question yet. Will a rear end from 48 Desoto car fit a truck? Or will the third member fit the truck housing? I mean fit a half ton 47-50 pickup? Quote Link to comment Share on other sites More sharing options...
Dozerman51 Posted February 21, 2018 Report Share Posted February 21, 2018 If your looking for a 3.73 or better ratio the ‘48 Desoto is not what you are looking for. The ratio of the third member should be 3.9. If he has the original engine it should be a a 236.6(237). Desoto did not install the 250.6(251) in their cars until 1951. Yes most post-war and some pre -war Desoto and Chrysler car third members will fit in the 1/2 and 3/4 ton truck third member housings. Some time in the early 1950’s though, the spline count changed in the pinion gears of the third members, so if you swap out a third member from those years, you need to also use the axle shafts from those third members in the swap or change the pinion gears from your third member into the later third members. If I am mistaken in what I’m saying, someone will be along to correct my Info. Quote Link to comment Share on other sites More sharing options...
wayfarer Posted February 21, 2018 Report Share Posted February 21, 2018 Unless there is an overpowering reason to use the old axle assembly then I'd be shopping for the Explorer 8.8 axle. As mentioned the Cherokee is also a good fit. Both are usually very reasonable in the Pik-n-pull yards. Newer axle= better parts supply.....and no tapered axles.... Do some searching, there are some threads on this subject. Quote Link to comment Share on other sites More sharing options...
dpollo Posted February 22, 2018 Report Share Posted February 22, 2018 the Desoto gearset will fit the half ton truck . However there is no oil fill plug on the Desoto's case, it is around the back. ( learned this the hard way) 3.73 was often found in Desotos of this era but your seller's count on driveshaft rotation sounds more like 3.9 or worse 4.1 and all are possible. The spline count for the axles changed for '53. Whatever engine is now in this Desoto, it started life with a 236 which is longer than your truck's original engine. It would not be practical to use a passenger car fluid drive in your truck because the truck's pedals and master cylinder mount to the bell housing. The FD unit itself may be the same as what was offered in the truck but you would still need the proper truck bell housing. what Dozerman says is essentially correct. Oil soup & Wayfarer may have offered the most practical solution. Quote Link to comment Share on other sites More sharing options...
doogan Posted February 22, 2018 Author Report Share Posted February 22, 2018 OK guys that settles it for me. I will forget the Desoto parts and start looking for a Dodge car or better yet the Jeep or Explorer. Wow!!!! The knowledge and experience from everyone here is just what us beginners need. Thanks again to all!! Quote Link to comment Share on other sites More sharing options...
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