I am looking into beefing up my 7.5 rearend. I have found a mini spool and a cover/girdle for my housing by Summit. I need to know of someone that makes a good 28 spline axle for my rear. It appears Moser Engineering only makes parts for 8.2 or bigger. I think there has to be a way with these parts to support high horsepower without taking out a loan just for a 9 inch rearend set-up. Any info or opinions will be appreciated.

 

See the tech articles:

https://www.thirdgen.org/newdesign/t...nguprear.shtml

and

http://www.isthq.com/~dan/10bolt.html

I went with Drivetrain Direct's HD 28-spline axleshafts, GM 3.42 gears, a HD Torsen diff, and all new bearings and seals. I'll be dropping in a 355 this spring and will bolt up some Drag Radials this summer, so we'll see how it does, but I know 4th-genners with stock 10-bolt rears running 12's and high 11's, although automatic trannies shock the drivetrain a lot less than 4000+ rpm clutch dumps.

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Greg Westphal
'87 IROC 305TPI/A4

 

I wouldn't use a mini-spool on the street. This will kill steering and stress the rear and wear the tires out. Mini-spools are only recommended for dirt track use.

 

Thanks for the information. These links have some very useful info. I am still open to anyone's opinion or experience with their 7.5 rearend.I plan on using a mini spool instead of a carrier.

 

Mini spool@ $99 or Limited slip @ $299, hmmm. This is my dilema with the carrier.

 

Or you can get the SLP "take-off" Torsen diff for $99. It's not the HD version (2 sets of worm gears inside instead of 1 set), but this diff has been standard equipment in the F-body since '99, and they're putting out well over 300 horsepower (under-rated by GM).

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Greg Westphal
'87 IROC 305TPI/A4

 

dont get a mini spool.....you'll be sorry. Those things dont work on the street - at all

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 224/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, 3000 stallconverter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
Best time yet to come
12's?? :crossthumbs:

This is a Pic of my car in race trim www.tbns.net/billyjay/camero.jpg

Yes I know how to spell camaro- so dont ask. I didnt make the link

 

You can use a mini-spool on the street, IF you don't ever have to turn. They are for dirt track for a reason, the dirt allows the tires to spin so you can turn. With good tires on clean pavement you will end up with an extreme amount of stress rear-end. Something will end up breaking. If you want some serious traction, get a powertrax locker.


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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

So you guys are saying a mini spool is not good for street use at all? I am just asking because I am looking at 500+ to the wheels and I do not think my stock limited slip will handle it. My car is a '89 so I have yet to discover if it is 26 or 28 spline. It does not matter because I am getting some good 28 spline axles from Moser. Is the powertrax better than a beefy SLP carrier? I think both are around $300.

 

I run a full spool on the street and don't really see the problem. Yes it is a bit harder on tires and yes you will not have a "canyon carver", but it makes the car VERY predictable. Since posi slip is elliminated, the car always launches the same. I will say it is harder on the car though. I run about 525 HP and would not have any other center section installed.

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1992 Pontiac Firebird 350/Six Speed
1987 Toyota Pickup 383/500+ HP

 

fine.....run a spool, better yet, just weld the spider gears together- thats safe. All Im saying is a lot of LS1 guys are using the same stuff as me in the rear (just a regular posi and 28 spline axels) and running in the 11's. If youre gonna have 525HP to the rear wheels then why skimp on a 100 dollar mini spool rearend. A zexel torsen diff from SLP is what you want!

 

How much is the Zexel center section? Is this section stronger than my stock one? I was wondering what it means when you say the spool is hard on the tires? Wear or turning?

 

the mini spool locks both wheels right? so when you try and make sharp turns, something has to give, whether it's the tires or and axle or maybe even the ring gear, depends on the type of tire(width or stckyness) or strength of your axles. Tires usually give first since one side is un-weighted when you make turns anyway, which is why you can run a spool on the street, but it is a gamble. If you do mostly highway driving it ain't that bad, but city driving will eventually fatigue one component in the rear. My friend use to run welded spiders just so he could drift. He'd have to re weld them every week or so, pretty retarded if you ask me

 

And the torsen rear is only $79 this week!

 

personally if i was running 500+ HP. i wouldnt worry about a few $ and i would buy what i needed. so what if you are in debt. BUY THE GOOD STUFF ONCE, OR BUY THE CHEAP A FEW TIMES. it all comes back in the end!
i would go with the ZEXEL TORSEN DIFF, not the spool, but its your car!! break what you please!

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Jarrad
1990 IROC-Z L98 350 TPI
TH-700R4
G92- 7.5" 10 Bolt 3.23gears
Bright Red Hardtop/ Grey Custom Interior
5,507 IROC's Hardtops/Ttops; 2,415 5.7L IROC's Produced in 1990

DAILY DRIVER: 1991 S10 2.5L/5SPD WITH CAMARO RIMS

 

Hi, Tadder!

500 horses through a 7.5" 10-bolt??? Don't waste your time and money trying to beef it up - you'll need a Currie 9" with 31-spline axles or a Strange 12-bolt - minimum. 7.5's aren't beefy enough to withstand that kind of power - they are marginal behind an honest 300-350 HP engine, especially with slicks and/or a stick shift. After spending almost as much as a stronger rear would cost, the 7.5 will blow and you'll have to begin all over again. I have to agree with the other guys about the spool - it'll eventually break axles on the street - you need a good, strong posi differential for what you propose!

Happy Motoring,

Harry

 

Some people underestimate the POTENTIAL strength of the 7.5"

I say potential because it earned a real bad rap with breakage. STOCK parts breakage. Mainly spider gears, axle splines, bearing caps, and ring/pinion gears (In that order)

I've seen many aftermarket carriers with richmond gears and a bearing cap girdle survive for a VERY long time with slicks.

Now sure, going with an aftermarket rear is the BEST idea if money is no object; but a properly prepped 7.5" will last at least long enough to justify the pennies on the dollar it takes to replace it (My theory) since junkyards just can't get rid of them, you have a lifetime supply of parts for almost free. I don't know about the rest of you and you guys probably think I preach WAY to much about junkyards, but I scored a SD computer, 2 PROMS, 2 Intrepid door handles with key (doin' a little conversion), a toasted 89 700R4 which I didn't have to pull, and a SD wiring harness for $100 from a local pull it this weekend.

Everyone thinks I spent a fortune on my car, but I'm not telling my secret (well it's out now)

Hell, I even get brake pads out of the yard. Smashed cars often have pads that are 95% or even better!

That leaves cash for things like carpet, seats, paint, food, beer....

I'm getting off the subject, but if I break a 7.5" rear I'm not going to cry. Haven't broken it yet and run 12's with slicks so I'll knock on wood.

How many 7.5" rears could I buy for the price of one aftermarket 9"? ALOT!!!

Bragging rights? Sure because you run faster with a 7.5". On an average 12 second car with slicks, you lose 4hp at the rear wheels with a 9" compared to a 12 bolt chevy. Now I know a 12 bolt chevy takes more to turn than a 7.5" so the number is even higher... Plus this doesn't factor in the weight savings.

Just junk foating in my head.....

 

These are some good opinions and statements from you guys. I made a decision not to run a mini spool. I will shop for an aftermarket carrier. Sounds like the majority of you guys go with SLP. I am going by one of the tech articles posted in this topic and start by welding the tubes. Does this carrier from SLP have a horsepower rating? Anyone pefer a different carrier than the SLP one for high horsepower?