Hey fellows;
I am still working on getting a 8 1/4 rear with 3.55, I can't find one in all of the junk yards around my area. This might be a dumb question to you guys in the know, but is there any other rear ends that will fit my 79 D100 rear wheel drive truck?

 

I would look for a 9 1/4 rear. Once they started using the overdrive It seems every thing was getting 3.55's If you want to stay with the 8 1/4 look in the vans also, just use the gears

 

TVLynn, can you explain. If I find a 9.25, it will fit, I don't have to re-weld the perches or do any major modifications? Also, the 9.25 comes with 3.55?

 

If you get one from a 1/2T pickup yes.. Van housings are different. I'm not sure of the measurement- may need to shorten the drive shaft IT may or may not have 3.55 You need to check the tab on the differential to make sure

 

Van axles are wider than the truck axles are. Anything up till 93 should fit your truck (spring perches and shock locations) but it needs to be from a 1/2T truck for the wheel bolt pattern.

Dodge kept the rear suspension on these truck on the outside of the frame in the rear (post suspension). Since the frames didn't change, the axles should line up perfectly.

 

I see! I found an axle from 1984 Dodge Van 10 bolt, 3.21. The guy says that it will not fit my truck but to me it looks the same. Is he correct? If I can use this axle my next question, is 3.21 a good street gear?

 

My 1992 D250 pickup 9.25" is 43" perch centers and approx. 65" wheel flanges.

Nose length is the same 8.25 to 9.25 so driveshaft length is not a problem but u-joint may be. This can easily be managed with a combination u-joint as I did.

 

Nope, Van axle does not have the same spring perch width and the wheel mount surface to wheel mount surface is wider than the truck axles. You need a rear axle out of a 1/2T truck. Only go with another gear ratio if you plan on swapping gears in the front axle.

 

78D200: the truck is 2 wheel drive. I am still looking an 8.25 rear. I found one but they want $500 I think is way too much. Hopefully one of the local junk yards will have what I am looking for and for a couple of hundreds.

 

2wd makes a big difference then. Go with whatever gear ratio you want.

And yeah, $500 is way too much for a 1/2T rear axle. Should be more like $250 or less. More like $125 if it needs brakes.

 

Thanks 78D200: I spoke to a guy from a salvage yard. He did not have the 8.25 diff but he told me that he was gonna try to put something together for me, even with a posi. He also talk about a drop axle. I don't know what he's got in mind but tomorrow I will find out.

On a side note, I was told that for the Dodge D100 truck parts were easy to find but I am finding out that around my neck of the woods, they are rare.

 

D150 parts are easy to find up here in the north east. The only difference with the D100 was the fact that it had the slant 6 motor and was more or less the "economical" 1/2T truck. Body panels, interior, lights, transmissions, axles, suspension (minus spring ratings), etc was otherwise the same.