About to upgrade my 7.5...please advise

[moose]

I've weighed my options and upgrading the 7.5 is going to happen. Please don't reply with comments saying I should get a 9" because I just signed a hefty student loan and with new brakes it's not in my budget. I have a 385 stroker with a th400, no idea of the hp/torque output (engine or at the wheels) yet, but it's definately less than 500hp. I'd say 400hp at best since that's what the builder estimated. I'm looking for some guidance because I don't want to waste money on labor (I don't have the time to try and do this myself or afford to make mistakes) or parts, but I don't want to waste money on overkill if I don't have to. This is my daily driver btw, after the swap I developed wheel hop and want to be prepared for winter since I now have much more torque.

I have UMI upper and lower control arms with roto joints waiting to be installed. New housing bushings, cover and 28 spline axles are no brainers. Timken install kit seems to be a standard? And I've been reading about using a solid spacer instead of the pinion support crush sleeve?

What about C-clip eliminators? I've read that they have a tendancy to leak and aren't really for use on street cars. I'm also hearing that they're neccassary if i'm planning on doughnuts and burnouts, which I know will happen.

Differential...it's down to either a Detroit Trutrac or Torsen T-2R. T-2R has a higher bias of 4:1 and a higher price of $675. I'm reading that the T-2R is basically the sh*t and worth the extra dough. However, the only opinions I can find on google are from auto cross/ drag racers. The Detroit has a 3:1 ratio, $390 tag, and I'm reading that there is a tendancy of only one tire to spin from all types of forums.

Experienced opinions are greatly appreciated.

 

[olds307 and 403]

Get ready to step up to 28 spline axles and a 7 5/8" posi and girdle cover. I have heard many good things about the torsen, only 28 spline axle posi, took 300+ hp factory in the F bodies. I broke the pins on my no slip with slicks. I just blew up the spider gears on my 7.5", took out the pinion and girdle cover. By the time you get aftermarket axles, new gears, posi and girdle cover plus set up, won't be far off the price off a 9" and much weaker. I am at around 275 hp/350 tq. Do you trust a ticking time bomb?

 

[cat herder]

Wheel hop will break even a 31 spline 9", even on street tires. I've done it. No matter which direction you go with the upgrade fixing that issue is a MUST.

 

[84cutlass383]

Differential...it's down to either a Detroit Trutrac or Torsen T-2R. T-2R has a higher bias of 4:1 and a higher price of $675

i can get u a 8.5 Gbody rear for $700 alot stronger than ur 7.5 rear

 

[moose]

i can get u a 8.5 Gbody rear for $700 alot stronger than ur 7.5 rear

Has it been rebuilt or is it in need?

 

[monte olrac]

take a look at this to give you some ideas

http://www.thirdgen.org/beefinguprear

 

[moose]

take a look at this to give you some ideas

http://www.thirdgen.org/beefinguprear

Thanks, this reafirms my thoughts that I don't need to waste money on a 9" for the street. Leaning towards the Torsen at the moment.

C-clips...anyone have something to say on whether they are good for the street/daily driving?

 

[cat herder]

If you don't do anything that will break an axle, c-clips are fine. Besides I'm not aware of an eliminator kit that works with the weird 3-bolt 7.5" housing ends.

 

[moose]

If you don't do anything that will break an axle, c-clips are fine. Besides I'm not aware of an eliminator kit that works with the weird 3-bolt 7.5" housing ends.

getting strange or moser axles, both have an eliminator kit for their axles

 

[cat herder]

http://www.moserengineering.com/moser/faq/#answer6

Can I use c-clip eliminators for street use?

A. We do NOT recommend using C-Clip Eliminators for street use; a C-Clip Eliminator is made for drag race only ( As a safety issue so you do not loose an axle, if it breaks ).C-Clip Eliminators are made for the straight shot down the strip. If you use C-Clip Eliminators on the street the aluminum block will eventually flex from cornering or just going around curves causing the C-Clip Eliminator to leak Rearend fluid.

Even ignoring that, I don't know how you bolt a 'universal' ("GM 10 Bolt & 12 Bolt axles except Impalas & Trucks") 4-bolt c-clip eliminator to the one-big-bolt-two-little-bolts flange on the stock 7.5" housing. Unless the kits require changing the housing ends, and they just forget to mention it.