8.8 swap questions

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Ok now that I understand that next question.
What proportionate valve do I need for the disks brakes on the rear? Will my original one work? My car originally has disk front and drum rear but with the rear swap I will have 4 wheel disks.
 
The few times I've done a disc conversion I cheated and used the MP adjustable proportioning valve in the rear brake line.
 
RustyRatRod said:
The few times I've done a disc conversion I cheated and used the MP adjustable proportioning valve in the rear brake line.
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What does that mean exactly? You ran two proportionate valve? One in the front and one in the rear?
 
You can run an adjustable one inline for the rears to adjust front to rear bias.
 
dartfreak75 said:
What does that mean exactly? You ran two proportionate valve? One in the front and one in the rear?
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I think I've done three. I know two....but there are shades of a third. lol I converted drum brake cars so they had no proportioning valve to begin with, just a distribution block. All I did was a regular 4 piston KH conversion in the front, did the disc conversion on the rear and plumbed in the MP adjustable proportioning valve in the rear line.
 
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See if @prorac1 will chime in. They just got done with Jason's car and they did this swap. Eric will tell you all about it.
 
dartfreak75 said:
Hopefully he will chime in with some pics because I am pretty confused Haha.
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Hey man, I know the 8.8 thread is ridiculously long. The posts for my son's car swap starts at #516. Right or wrong IDK but I used an oem prop valve. Seems to work fine. Plus we cut it and had it replaced in a couple days. Did an easy cross over on the park brake cables. See what you think.
 
I went over and rear all that in the 8.8 thread. I still have a some info I'm missing.
1) does the 457 u joint fit the factory Ford flange yoke or do you have to change it?
2) does this require modification of the factory a body driveshaft?
3) what shock mounts are you using?
4) what spring perches? Will any 3 inch perch work?
5) where did you find that pipe cutter? I looked on Ebay and they arent cheap the cheapest no 3 I have found is around 100 bucks.
6) when you welded your spring perches on what angle was the pinion at? This is a major concern for me.
 
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I guess. If you look at the application chart all it lists are GM products. I don't know if that as the same size line fittings as the Mopar or not.
 
RustyRatRod said:
I guess. If you look at the application chart all it lists are GM products. I don't know if that as the same size line fittings as the Mopar or not.
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That's a good point I didnt notice that. I already have all the new fittings and brake lines so I dont want to rebuy all that.
 
dartfreak75 said:
I went over and rear all that in the 8.8 thread. I still have a some info I'm missing.
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1) does the 457 u joint fit the factory Ford flange yoke or do you have to change it? Fits
2) does this require modification of the factory a body driveshaft? Yes. Needs to be shortened about an inch.
3) what shock mounts are you using? Cheapest I could find for an 8 and 3/4
4) what spring perches? Will any 3 inch perch work? Pretty much.
5) where did you find that pipe cutter? I looked on Ebay and they arent cheap the cheapest no 3 I have found is around 100 bucks. Pay the shipping and you can borrow mine. Only been used once.
6) when you welded your spring perches on what angle was the pinion at? This is a major concern for me. I already forgot, lol. I think it was down a degree or two?
 
That was a factory sb and 904 shaft, btw. Don't know about your /6 904 shaft.
 
moparmandan said:
1) does the 457 u joint fit the factory Ford flange yoke or do you have to change it? Fits
2) does this require modification of the factory a body driveshaft? Yes. Needs to be shortened about an inch.
3) what shock mounts are you using? Cheapest I could find for an 8 and 3/4
4) what spring perches? Will any 3 inch perch work? Pretty much.
5) where did you find that pipe cutter? I looked on Ebay and they arent cheap the cheapest no 3 I have found is around 100 bucks. Pay the shipping and you can borrow mine. Only been used once.
6) when you welded your spring perches on what angle was the pinion at? This is a major concern for me. I already forgot, lol. I think it was down a degree or two?
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Good info thank you when I get closer I will shot you a PM for the cutter thank you for that I appreciate it
 
dartfreak75 said:
I went over and rear all that in the 8.8 thread. I still have a some info I'm missing.
1) does the 457 u joint fit the factory Ford flange yoke or do you have to change it?
2) does this require modification of the factory a body driveshaft?
3) what shock mounts are you using?
4) what spring perches? Will any 3 inch perch work?
5) where did you find that pipe cutter? I looked on Ebay and they arent cheap the cheapest no 3 I have found is around 100 bucks.
6) when you welded your spring perches on what angle was the pinion at? This is a major concern for me.
Click to expand...

3. Your spring plates may need to be modified to fit the new u bolt width, ie slotted or hit a boneyard to find one that will work. If plausable move brackets from existing rear for shock mounting.
4. Measure your spring width then your tube diameter, several sources both on ebay or Summit and Jegs with new perches. I got mine off an old truck 9" I had laying around.
5. If you take your time and have a steady hand use masking tape to mark it square and use a cutoff wheel on angle grinder etc.
6. There are apps for your phone that are angle finders the angle is a combo of your output shaft angle and pinion angle. Others can get you in a ballpark with #'s
 
moparmandan said:
That was a factory sb and 904 shaft, btw. Don't know about your /6 904 shaft.
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Ok gtk! Mine is a slant six driveshaft. IIRC /6 and v8 had the same length driveshaft. I have a buddy that his dad works a driveline shop I bet he could shorten it for me
 
Stephen Hotz said:
3. Your spring plates may need to be modified to fit the new u bolt width, ie slotted or hit a boneyard to find one that will work. If plausable move brackets from existing rear for shock mounting.
4. Measure your spring width then your tube diameter, several sources both on ebay or Summit and Jegs with new perches. I got mine off an old truck 9" I had laying around.
5. If you take your time and have a steady hand use masking tape to mark it square and use a cutoff wheel on angle grinder etc.
6. There are apps for your phone that are angle finders the angle is a combo of your output shaft angle and pinion angle. Others can get you in a ballpark with #'s
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Good info.
I was going to mention it but didn't because the factory spring plate/ shock mount can be made to work. But it really jacks the bottom shock rubber out of whack. But it WILL work to get you going.
And I am not good with a torch so there was no reusing my spring perches. LOL
 
dartfreak75 said:
Do you think that cutter will cut a driveshaft as well? Or is the driveshaft too big around? I could probably weld it up myself if I could get the cut perfectly straight!
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Absolutely. I was going to do that myself but it really needs to be balanced. Again, not a problem if it's just to get the car moving. Some guys are pretty good at doing a home balance.
 
moparmandan said:
Good info.
I was going to mention it but didn't because the factory spring plate/ shock mount can be made to work. But it really jacks the bottom shock rubber out of whack. But it WILL work to get you going.
And I am not good with a torch so there was no reusing my spring perches. LOL
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Yea I'm not even gonna try and save them I found some mopar brand 3" perches for 22 bucks. I may and try to modify my original 7.25 shock mounts to work we will see when I get there.
 
moparmandan said:
Absolutely. I was going to do that myself but it really needs to be balanced. Again, not a problem if it's just to get the car moving. Some guys are pretty good at doing a home balance.
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I will see how what time frame between rear end going in to engine going in is? I dont want to cut the driveshaft before I can match it up to the engine and I dont want to keep your tool to long Haha
 
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