8.8 swap

[moparmat2000]

Great idea, I was considering something very Similar like this, along with a LCA bumper on top. Then I just got a set of Jegs universal slapper bars. Going to prob use those and paint them black. The thought of cutting that out of thick assed steel plate was a deal breaker for me. You may be able to make that adjustable though.

 

[moparmandan]

Great idea, I was considering something very Similar like this, along with a LCA bumper on top. Then I just got a set of Jegs universal slapper bars. Going to prob use those and paint them black.

Yeah will definitely need something rubber on top.

 

[moparmat2000]

Keep a hole in the middle under the square stock tubing to feed a socket up there with a nut for a front suspension bumper. I may still consider copying this off you.

 

[moparmat2000]

jrlegacy23 what did you use to weld the tube to the cast housing? I have a solid core mig but didnt figure that was possible.

 

[jrlegacy23]

MoparmanDan, I really like that design, it looks like it will function well. How does it line up under the car?
What I see being a placement issue in MoparMatt2000's pic is the space constraints. There is not a lot of space between the Ujoint and the tunnel (and no tunnel support there), causing it to not work efficiently.

 

[jrlegacy23]

jrlegacy23 what did you use to weld the tube to the cast housing? I have a solid core mig but didnt figure that was possible.

I used MIG. I was told by some that said to use a high nickel content rod because it is cast iron. But I had a welder look at it and said that it was cast steel. He told me that I can use a regular MIG (just preheat cast, it will hold fine for what I am putting in front of it (400hp small block). He did tell me that the nickel rod would be better but not a necessity with cast steel. It welded, really no differently.

 

[moparmat2000]

jrlegacy23 which picture?

 

[jrlegacy23]

jrlegacy23 which picture?

The first rear I did was a high nickel content TIG weld.

The second rear I did was preheated and welded with a MIG

 

[moparmat2000]

MoparmanDan, I really like that design, it looks like it will function well. How does it line up under the car?
What I see being a placement issue in MoparMatt2000's pic is the space constraints. There is not a lot of space between the Ujoint and the tunnel (and no tunnel support there), causing it to not work efficiently.

I meant which pic about space constraints ? If it had something to do with me considering adapting the 7.25 pinion snubber to the ford axle. I abandoned that idea. I think the moparmandan idea is more simple and realistic. As long as it lines up with the transition pan reinforcing plate. A good idea would be to measure the 7.25 from centerline forward to the snubber bumper, and try to make the one for the ford axle to sit in the same spot and about the same height or a little higher. I may still build one like Dan's design and ditch the slapper bars altogether. Not a big fan of those but figured they were better than nothing.

 

[moparmat2000]

Can you buy high nickel steel mig wire?

 

[jrlegacy23]

Can you buy high nickel steel mig wire?

https://www.airgas.com/product/Weld...-&-SAW)/MIG-Wire---Nickel-Alloy/p/AH2S625XS30

I meant which pic about space constraints ? If it had something to do with me considering adapting the 7.25 pinion snubber to the ford axle. I abandoned that idea. I think the moparmandan idea is more simple and realistic. As long as it lines up with the transition pan reinforcing plate. A good idea would be to measure the 7.25 from centerline forward to the snubber bumper, and try to make the one for the ford axle to sit in the same spot and about the same height or a little higher. I may still build one like Dan's design and ditch the slapper bars altogether. Not a big fan of those but figured they were better than nothing.

I was just making conversation in regards to different ideas and concepts to make a pinion snupper.

 

[moparmandan]

It'll all prove out (or not) when I get the diff under the car this weekend. Sooner or later this car will have enough balls to really need one, and it's way easier to make it now.................

 

[moparmat2000]

I may do some measuring tonight on my roller 7.25 axle, and look at the 8.8 to see where the snubber rubber would need to be located.

 

[moparmat2000]

A body 7.25 from axle centerline forward to center of the pinion snubber rubber bumper is exactly 10" forward of the axle centerline. The second pic taken at the 8.8 axle centerline puts the center of the snubber bumper above the yoke on the 8.8 or about where it is on the 7.25. The rubber bumper is also located 5" above the axle centerline on the 7.25.

Looking at typical wear marks on the transition pan reinforcements being typically dead center, I would say the one moparmandan wants to build will completely miss the reinforcement on the transition pan. Using the center point of his vertical support as a guide for a bumper, it would need to be 2.5" farther forward to make that 10" where the bumper center would need to be".

It's a great idea, and I briefly considered it before abandoning it. Now I remember why. IMHO, I dont think having a beefy snubber like that mounted that far forward to contact the floor pan, but only attached to the side of the axle housing is going to be very good on the housing in the long run with repeated hard launches. I will likely stick with black painted universal slapper bars.

 

[moparmandan]

Thanks! All good info and some issues that I will think about. Maybe even a collar underneath the diff to reinforce things, sorta like the Mustangs have. Maybe extend and reinforce the floor pan contact area. idk. I know slappers work, but.......Maybe some homemade caltracs...........

 

[Dartfreak75]

@moparmandan what where the measurements you used for the spring perches?

 

[moparmat2000]

I have not set mine up yet but heres my idea that's been running through my head. It may seem like a lot of steps but it will ensure the rear is square and centered with a proper pinion down angle.

1 New polyurethane bushings on both ends of the leaf springs including on the rear bolt in mount.

2 Bolt up leaf springs at the front but do not super tighten the bolts. Leave them relaxed to pivot.

3 Set perches in place on the springs, and set axle on them.

4 Loosely install U bolts and shock plates so they are loose enough to move the axle side to side in the perches, and allow the springs to bolt up at the back end

5 Jack up the rear and install rear shackles. Fully Tighten the spring bolts tight front and rear to square up the springs.

6 Now you measure and adjust it side to side until its centered. Then tighten the U bolts snug to hold everything. Do NOT attempt to drive the car this way. This is only for mocking up the axle. I plan on spraying the tubes with blue machinest dye before I set it in place. Once I get the side to side measurement set in place, I will scribe a mark into the dye right exactly where the perch is against the tube so I know where to set the perches.

7 take the rear back out and set on saw horses and set perches on scribe marks.

8 position perches and axle with degree protractor to set a 5° down angle from square to the pinion

9 tack weld the perches in place and double check the 5° down angle.

10 weld up solid.

11 crack a beer and enjoy.

 

[Dartfreak75]

I have not set mine up yet but heres my idea that's been running through my head. It may seem like a lot of steps but it will ensure the rear is square and centered with a proper pinion down angle.

1 New polyurethane bushings on both ends of the leaf springs including on the rear bolt in mount.

2 Bolt up leaf springs at the front but do not super tighten the bolts. Leave them relaxed to pivot.

3 Set perches in place on the springs, and set axle on them.

4 Loosely install U bolts and shock plates so they are loose enough to move the axle side to side in the perches, and allow the springs to bolt up at the back end

5 Jack up the rear and install rear shackles. Fully Tighten the spring bolts tight front and rear to square up the springs.

6 Now you measure and adjust it side to side until its centered. Then tighten the U bolts snug to hold everything. Do NOT attempt to drive the car this way. This is only for mocking up the axle. I plan on spraying the tubes with blue machinest dye before I set it in place. Once I get the side to side measurement set in place, I will scribe a mark into the dye right exactly where the perch is against the tube so I know where to set the perches.

7 take the rear back out and set on saw horses and set perches on scribe marks.

8 position perches and axle with degree protractor to set a 5° down angle from square to the pinion

9 tack weld the perches in place and double check the 5° down angle.

10 weld up solid.

11 crack a beer and enjoy.

View attachment 1715498041

That's kinda what I had in mind too. I'm am concerned about getting it centered by myself I dont have a garage floor to move around on so its gonna be alot of jacking lifting pushing and pulling lol

 

[moparmat2000]

I plan on doing this while the floors are out, and the rear axle is an empty housing. This will make it a lot easier. When I get it done I plan on measuring everything, and posting the measurements. Of course **** always happens at my house that impedes forward progress on my projects, so if you need it installed right away dont wait on me

I am waiting on the custom shock plates I have being made I was talking about that have enough room for the U bolt nuts. The perches will be 1/4" thick steel and the holes will be slotted for 3" to 3&1/8" axle tube. Of course Covid 19 has put a damper on everything, so it's slow going.

Once I get my first set and prove em out along with pix, I will see about getting more made to sell on here to guys doing the swap. That wont be as slow going as my project is

The problem with the factory 3" mopar shock plates is you can slot the holes 1/16" on each side opening them up for the wider 3&1/8" Ford U bolts but the holes are so close to the end flanges you cant properly fit nuts and washers.

First picture is a model showing the extra space you have for nuts and washers before the 90° bend on the end. Shock will retain its stock location with these. These will be a better way to go with this swap than slotting original plates and having a compromise that IMHO is not going to clamp everything together as well.

 

[moparmandan]

@moparmandan what where the measurements you used for the spring perches?

Uhhhh, I think it was 43"
About 2 5/8" from the flange?
I've slept since then, lol.

Angle, I basically did what has been discussed. Put it in, check it, tack it, pull it, weld it.

 

[Dartfreak75]

Uhhhh, I think it was 43"
About 2 5/8" from the flange?
I've slept since then, lol.

Angle, I basically did what has been discussed. Put it in, check it, tack it, pull it, weld it.

43ish is what i got on my 71/4 so that sounds right did you use the factory location in yours as well?

 

[moparmandan]

43ish is what i got on my 71/4 so that sounds right did you use the factory location in yours as well?

Yes i did. I had an old 7 1/4 sitting close by. And my car. And my son's car. And everything was different a little, lol. Threw it all together and baked a biscuit.

 

[Dartfreak75]

You got plenty of tire clearance with that stock spring location and the 8.8 I'm a little concerned about it but I really dont want to pay 175 for the 1/2 kit.

 

[moparmat2000]

dartfreak75 It's only about 3/8" narrower per side than a mopar 7.25. That's not very much. If you really had to and, I dont think you would need to, you could put longer studs and some 1/4" thick spacers on.

 

[Dartfreak75]

dartfreak75 It's only about 3/8" narrower per side than a mopar 7.25. That's not very much. If you really had to and, I dont think you would need to, you could put longer studs and some 1/4" thick spacers on.

Ok thanks man I guess I I'll mock it all up and see what it looks like I havent got the money right now to order my new springs will they change the pinion angle or is that strictly based off the location of then hanger on the axle?