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Discussion Starter #1
#1. Is this what I need to order for rebuilding the pumpkin?

http://www.summitracing.com/parts/FMS-M-4210-C/?rtype=10

It says for 86-04 mustangs..so its for a solid axle rebuild. I guess the only parts I worry about are the axle bearings and seals on the side of the pumpkin...


#2. Im going with an explorer 302 and am ordering a 3.55 gearset...I know its a hornets nest, but anyone want to try and talk me out of it? I plan on cruising with a little spirited cornering hear and there...not drag racing..standard t-5 from donor mustang.

#3 My hubs are at Stu's as we speak for re-drilling the bolt pattern...
What are my CHEAPEST disk options? t-bird disks also re-drilled or will some other model car disks just fit right on?
 

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I am doing an IRS car now and have built one before.

My build rule...keep it simple. Try something different and you will regret it.

I am not sure what you posted from summit, but my suggestion is to find a early 90's thunderbird center section or complete clip.

Buy a good used lincoln mk8 center section and simply transfer the internals from one to the other. You can do the 3.55 swap at the same time.

I am not sure the mustang stuff totally transfers because the IRS axles clip in place
 

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I think there are two kits of parts you will need, these are what i used on my 95' t-bird housing and they are made for the IRS chunks. I put in a new Auburn diff since my t-bird chunk was open diff and used the factory 3.27 gears since ill be cruising with a BBF.

M-4210-B - rebuild kit w/ pinion bearing and seal
M-4413-A - axle shaft seals/bearings

As far as brake rotors i got some t-bird rotors and re-drilled them. Rebuilt the t-bird calipers. If you are rebuilding the chunk yourself there is a handy little doodad (Ratech 10006) that you can use to set up pinion depth with a pair of calipers. Worked pretty good for me, which all I had to do in the end was pop the factory shim back in it since i was using the factory ring/pinion. HTH
 

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Discussion Starter #4
I am doing an IRS car now and have built one before.

My build rule...keep it simple. Try something different and you will regret it.

I am not sure what you posted from summit, but my suggestion is to find a early 90's thunderbird center section or complete clip.

Buy a good used lincoln mk8 center section and simply transfer the internals from one to the other. You can do the 3.55 swap at the same time.

I am not sure the mustang stuff totally transfers because the IRS axles clip in place
Hmm...maybe I didnt make it clear. I have a donor IRS..Im rebuilding the pumpkin which I already have...wondering if the part kit was the correct one.
 

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M-4210-a for the irs

We sell for $40.00 & have in stock

3.55s are a good all around gearset $159.00 in stock Ford gears
Steve
 

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It would be best to get hold of one of our vendors to be sure you get the right parts the first time.
Either Mike at Forte's or Max at Five Star Ford to get the correct parts for your rebuild. Either of them will know exactly what you need.
I don't see a clutch pack on your list. As long as you are rebuilding the differential, you may as well go ahead and rebuild the clutch pack so you don't have to do it again at a later date.

Bob
 

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Look at the Tag on your differential looking for two things... Gear Ratio and L for Locking... If you got it from an automatic the gears are probably 373's which is very darn close to 355's. A lot of guys just run those.. If its a locking diff then the kit would work... There is a difference between the two rears, but you already have the internals that take the axles that lock in place with the retainer clips.. When I say locking in I am referring to two different things. Gear ratio and L for traction lock and the internals made for the retainer clips.. You must have the one with L for traction lock, for the Summit kit to work. Same rebuild parts for both rear ends, with traction lock. The traction lock for the Cobra IRS Rears (2003 mustang ) uses carbon fiber clutch packs,is the only one that's different...
 

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Irs rear end

Hi
All the parts for the IRS pumpkin and the 8.8 straight are the same except for the axle seals and axle bearings. If you can,t find the IRS seals & bearings we have them at
www.discbrakesrus.com Note; the link at the bottom of this page dose not work. and I will be damed if I know how to fix it.
 

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Discussion Starter #9 (Edited)
Look at the Tag on your differential looking for two things... Gear Ratio and L for Locking... If you got it from an automatic the gears are probably 373's which is very darn close to 355's. A lot of guys just run those.. If its a locking diff then the kit would work... There is a difference between the two rears, but you already have the internals that take the axles that lock in place with the retainer clips.. When I say locking in I am referring to two different things. Gear ratio and L for traction lock and the internals made for the retainer clips.. You must have the one with L for traction lock, for the Summit kit to work. Same rebuild parts for both rear ends, with traction lock. The traction lock for the Cobra IRS Rears (2003 mustang ) uses carbon fiber clutch packs,is the only one that's different...
Well I actually have 2 rear ends...one off my donor and the irs donor...the irs came with 3.08...I really had to whack the heck out of the pinion to get it out...signs of overheating in the past Im told...so its shot...I think the one from the mustang is 3.27 but Im not 100% on that...Ill think about using it if its 3.73.

Edit: it is a 3.73..might think about that..also Ill hit one of the forum sponsors for the rebuild parts...thanks for pointing me that way.
 
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