ihengineer76

Looking for a good (or one that needs clutches) posi carrier for an 8.5" 28 spline differential (2.73 and up) I already have 3.42 gears.

Thanks much.

Tom

Allan R

Check with 507OLDS (Brian Trick) or Monzaz (Jim Mitschke). That's what they do for a living.

507OLDS

I have them,used,rebuilt,and new.

ihengineer76

How much would you want for a used Detroit Truetrac or a rebuilt Eaton?

507OLDS

A Tru-Trac would be new.
A rebuilt Eaton would be $375.00
A rebuilt GM clutch style posi unit would be $325.00
A new Yukon unit is $375.00,and is a copy of the Eaton.
The new Eatons,and the Yukons,come with a polycarbonate clutch.
I install the original style knurled steel clutches on the units that I rebuild.

ihengineer76

Would the GM unit hold up to 500hp? I'm running 3.42 gears and a 4 speed. If you don't think so, then I would take a rebuilt Eaton.

507OLDS

Yes,it would,but remember,it's not the HP,it's the torque.It's the blunt force that you throw at it.A stick-shift or trans-brake will also amplify that force.What are your plans or expectations with the car?

ihengineer76

Its going behind a built 362, but I see 550 ft-lbs being the max. The car will be street driven with weekends at the strip. Possibly running slicks and also the car is a 74 Cutlass so its a little on the heavier side.

507OLDS

Yes,it would be fine.However,since you are starting from scratch,now would be a good time to upgrade to 30-spline axles,and a posi unit to match.Not a must,but a good time to do it.

ihengineer76

I will take the GM diff, but I think I'm going to run the 28 spline axles for now. I have to save some stuff for next summer. I was actually thinking of building another rear end with 4.11's and 30 spline axles for racing, then I could just swap out differentials and still have gears suitable for cruising. I will pm you my info for shipping and stuff.