7.5 rear suggestions

[mudpaws]

I know you're against it but I did the 8.8 swap and its great. The rearend is now not even a concern of mine...

$125 complete rearend
$50 clutch kit
$75 new bearings
$260 Instant Center correction kit
$90 brake lines, pads, rotor resurface
-------------------------------
=$600 New readend plus adjustable control arms and rear geometry

did you buy a Mustang 8.8?

 

[dlo253]

Sorry to thread jack. Seems you figured your situation out for the most part, and I don't feel my question warrants its own thread. Just wanted quick confirmation from the group. New rear is not in the budget nor do i think it is needed yet at this stage of my build. Was going to get a 7.5 posi kit from Quick Performance... But after some reading it seems i could get the 7.625 kit from them along with a set of 28 spline moser axles for a GN..? Everything is the same cost so if it will all fit in my rear obviously i would do that. Just want to confirm that i am correct in thinking that. Again, sorry to thread jack. Figured i would try this before making a thread.

 

[Bar50]

Don't get hung up on the 7.5 or 7.625 the main thing is you need a 28 spline posi and 28 spline axles.

 

[dlo253]

Sweet, only reason i specified is because i didnt see a 28 spline option that was listed as "7.5". Just want to be extra sure everything will fit in my current rear before spending the cash lol, thank you.

 

[Speedy94c]

400HP on 7.5 or 7.625 will work woth street tires for a long time, but with sticky tires , a suspension built to launch, and a 3000+stall it's a time bomb. It's the shock load from launching hard that will destroy it. If that isn't in your plans, then you'll be fine. I migh have mentioned this before, but we ran a 7.5 with a used Torsen from a late 90's Camaro with S10 axles for a full season of spirited driving with drag radials.It also has a girdle. We were making 400+whp (not crank) and it looks like new inside. We also used a set of junkyard 3.42 gears.

You're cheapest way out (and functional) is to find a used Torsen - $150-200, a bearing kit - $80, and a set of Moser axles - $280 shipped.

The rear I described above is now our spare. We did upgrade to a GN 8.5, but went with a 31 spline clutch posi and Moser axles. But we're making well over 500whp now and figured the 7.5 with the Torsen wouldn't take it for long. Our car is daily driven (hard), and if we ever manage to break to the 8.5, then we can swap out the complete 7.5 in 3 or 4 hours and run it until we decide what to use next. Just have to use our heads when driving it. And FWIW, we have $1800 in the 8.5.

Someone posted that it is easier on the rear with taller gears - that is incorrect. A set of 2.29's will smash the axles or pinion gears long before a set 4.10's - it's simple phyics.

So are you telling me that I could use s10 axles with a 28 spline carrieer out of a later F body rear end?

 

[pontiacgp]

Sweet, only reason i specified is because i didnt see a 28 spline option that was listed as "7.5". Just want to be extra sure everything will fit in my current rear before spending the cash lol, thank you.

If you want to leave the 7.5" rear housing you can use the 7.5" Eaton truetrak 28 spline and get yourself some 28 spline axles.

 

[64nailhead]

So are you telling me that I could use s10 axles with a 28 spline carrieer out of a later F body rear end?

Yes

 

[olds307 and 403]

Are S10 axles the right length? The main reason the 7 5/8" carrier is superior to STOCK 7.5" is the more evenly sized spider gears. Another reason the Fbody Torsen posi is a good option. One of the first things to explode in a 7.5" rear is the spider gears, ask me how I know.

 

[Speedy94c]

From what ive read and researched the 4x4 ones are 1/2 longer, so I dont know how this would effect if you have drum brakes, If you were running disc then it wouldnt be a problem just have to move the caliper bracket.
The 2 wheel drive ones are 2" too short so I dont think they will work at all.
I have an extra 7.5 open housing im going to do some playing around with to see if I can make it work with the s10 axles out of a 4x4 when I get time.

 

[pontiacgp]

From what ive read and researched the 4x4 ones are 1/2 longer, if you have drum brakes, If you were running disc then it wouldnt be a problem just have to move the caliper bracket.

I would never suggest to use an longer axle even if you move the caliper bracket. First reason is the axle is machined so the axle bearing rides on it and I would think on a longer axle the bearing would not be riding on that part of the axle. Second reason is with the longer axle there is more axle on the outside of the axle bearing which puts the wheel further out. That means there is more leverage on the axle which could cause the axle to break from stress