Hello all, long time reader first time poster. My ride, 1973 Scamp, 225, PS, drum brakes and not much else. We've done some up-grades I'll post them and pics another time. On order is a disc brake up-grade from POL. Changing to LBP. Was going to address the rear end in the future but I came across this CL post "For sale used 1973 Plymouth Satellite 8-1/4"rear end 2.73 gearing. lug pattern 5 X4.5 width 63". It's dirt cheap so I'm wondering if I should grab it. Pretty sure it will need some work to fit it but my rear end Kung Fu is weak. Any help/advise is much appreciated. Thanks for your time.

I would look for an 8 1/4 from a 74-76 A body. It will obviously bolt right in and you should be able to locate one with the larger bolt pattern. We did this to a 70 Duster once from a 74 Dart donor car.

_________________
-MattMan
LEANED & MEAN

'73 B-body rear end is too wide for an A-body. A factory A-body is a direct fit or a '68-'70 B-body will fit with some minor modifications. I don't know if an 8 1/4 was ever put in a '68-'70 B-body but I have an 8 3/4 b-body rear in my '76 a-body.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

8 1/4" was available for HD packages and the 1973 340 cars(last year for the 340...my Feather Duster currently has one from a 1973 340 Duster since the owner went to the Dana 60...)

Be careful that some versions (like the 74 318 A-body could be had with the 2.45:1 ratio, and the first manufacture versions dating to late 1972 for the 1973 model year could have the 2.56:1 ratio)...
If it comes with either you will have to replace the case as it won't support gear ratios 2.76-4.56...FYI.



As I remember right the 8 1/4" first showed up in base model 318 B-bodies in the 1969 model year... which brings up another issue:

The 8 1/4" made some changes to about 1972 and again somewhere in the mid-70's, the change only affects the pinion and bearings, so make sure to note
which year you have or record the axle assembly part number after you clean the assembly up, that way if you have to take it to a shop for a ratio change
or to replace the axle shaft bearings, your car isn't sitting around for 3 weeks while they get bearings, find they don't fit, then send them back and try the next set...

Thanks for the replies,

Badvert65, A body donor cars are very very scarce here in the Bay Area. Took years to find the right Scamp, aka Grumpy. Heck even the central valley is picked clean.

afastcuda1970, yeah that was my suspicion, too wide. But dude is only asking for $100. Was hoping it would be a proper candidate to take to the local shop for a shortening. Cut cut here, weld weld there, get the axles cut, re-splinded, new wear items and bam. Bolt it up.

DusterIdiot, I dig what you're putting down. Years past we've built a few mismatched vehicle. The Frankenbronco was the pinnacle, had to keep a list of the donor vehicles for parts ordering.

Looks like I should pass on it. It's cool cause the first of the front disc swap parts have arrived. YeeHaw!

The problem here is that the Mopar 8 1/4" and later 9 1/4" rear axles are retained by C-clips in the case....so even if you plunked the money to do all that, you'd be out the extra labor to have them get the runout and tolerances correct to machine the clip groove...(by the time you're done you'd have probably almost paid for an 8 3/4"....and if they goof up you'll loose an axle shaft turning a corner as the clip unloads on one side and slips out...

@ DusterIdiot, thanks for the info. Agreed not a viable solution. As the blind man once said "Now I see". Good news though, all front disc parts are in. Time for some fun....