Question for those who have swapped a 8-3/4 Mopar into a WC or WD truck

[lostviking]

First off, what springs did you use? Did you change transmissions also? Did you put the tubes over or under the springs?

 

TIA.

 

After looking at the cost of getting either an 8.25 Mopar or an 8.8 Ford, and then rebuilding them...it seems like a better idea to order an 8-3/4 from a guy selling them on the Mopar group on fb. Even with shipping it seems like I'd get the whole thing done for about the same cost and I don't have to do it. Not that I mind, but that does factor into the cost.

 

If I go that route I'll have him weld the perches to the correct width for my truck.

 

Thoughts?

[Tooljunkie]

I used 8-3/8” from a 75 d100.

its pretty much the same as 8.25. My only concern is pinion angle. If he can supply perches, great! But you need to set pinion angle.may want to  provide spring width, so you get the correct ones 
 

i did a 8.25 a while back, seals, and all new brakes. Was $300 in parts. Including a new pair of drums. 

[lostviking]

Pinion angle changes that are fairly small can be set using wedges. I've seen that done on extreme 4x4 builds. I'll need to work on that though as I'm moving the mount from under to over, so it won't be the same as now. That said, being more inline with the trans exit, the angle would be less.

 

I'm going to send him the width of the locating stud for the springs. I haven't worked out all the details or spoken to him. He might only off the perches in the stock location.

 

The 8-1/4 uses c-clips to retain the axles. Not my first choice. But more importantly I've been inside the 8-3/4 many times and I can do drum of disk. I know you can get 8-1/4 with disks, but that is a different bolt circle if I'm correct.

 

I 8-1/4 on ebay is around 450-550. That would need a full rebuild before I ran it, so bearings also. I think it's more like 500-600 in parts. I could be wrong, but that's what I've seen reported. Shipping is 250, and mostly only to a freight shipment point. I don't have a truck to go get it. To my door people have quoted me 450. Add it all up and I like the 8-3/4 idea best.

 

Anyone have comments on springs? Stock replacements? I have a 3/4 ton, so I'm not excited about the option of just buying new 3/4 ton springs. They are very stiff if you don't plan on using it as a work truck. Other options are highly desired for me.

 

Thanks for responding.

 

Tim

[lostviking]

After looking at all the options, I just pulled the trigger on a Mopar 8-1/4 inch with 3.55 gears. It was less than $500 shipped to my house from B&R auto wrecking. It's more than I need strength wise and seems to be a good fit for our trucks. Thanks to all of you who blazed the trail and posted your information in the various threads.

 

Tim

[The Oil Soup]

That is what I used on my truck and am happy with the gearing but I may consider using a Laycock J Type overdrive to retain the 3 speed on the column and lower cruising rpm. 

[lostviking]

Hmm. Well I guess that makes me feel a bit better. I was still unsure about going with the 3.55 instead of 3.73. I didn't want the gearing to get too high and make first gear a clutch slide. As long as I can comfortably do 65 I'm good.