56 Chevy rear axle?

[Alan Nyhus]

If you're going to use a posi setup, I'd call Tom's Differentials and talk with them.

I remember that some of the differentials has 8 plates and some had 10. The spider gears were also a weak spot but I believe Tom's makes replacement high strength spider gears. They've been doing these '55-'64 style drop outs for a long time...many of the 409 guys use their stuff. Might be worth the call if you're committed to using a posi. -Al

https://tomsdifferentials.com/toma.html

[Dwight Southerland]

Originally Posted by Alan Nyhus

If you're going to use a posi setup, I'd call Tom's Differentials and talk with them.

I remember that some of the differentials has 8 plates and some had 10. The spider gears were also a weak spot but I believe Tom's makes replacement high strength spider gears. They've been doing these '55-'64 style drop outs for a long time...many of the 409 guys use their stuff. Might be worth the call if you're committed to using a posi. -Al

https://tomsdifferentials.com/toma.html

X2!

[Jeff Stout]

My first car was a 55 Chevy in 1976. 327 4speed. I broke so many spider gears. As soon as the car wheel hopped bam. If I had only knew at the age of 16 this trick.

[Mark Yacavone]

We had Chrysler side gears and Henry's Axles in 1970...because we had to.

What are we building here?

[Aubrey N Bruneau]

I designed a complete kit for running these rears, which I use in my 62. The Dana "powr-lok" design posi unit is available brand new, already prepared with the 30 spline side gears in it.
Also, bearing cap re-enforcement is mandatory.

[jmantle]

[QUOTE=Mark Yacavone;618405]We had Chrysler side gears and Henry's Axles in 1970...because we had to.

Likewise, Chrysler side gears, Henry's axles, shim the clutch pack tight, torque up those weird left hand bolts, then weld the two halves together. Add steel caps and longer cap bolts and it might be good for a few runs with a stick car. Not sure when we first tried this, 67 or 68.

Jim Mantle V/SA 6632

[Bob Mulry]

I still have a couple of hams on the shelf that have Stahl & Associates heat treated MOPAR posi side gears to go with my Henry’s Axles in my 1962 Corvette

You also need a steel bearing cap and stack the posi plates 1 internal tang and 1 external tang to make it a locker....

I also welded a doubler plate and 1/2-20 nut to the rear of the housing, so I could tighten it up against the cap for strength....

Don’t forget there are 2 types of posi cases, 1 with 90 degree ramps and the other 120 degree ramps...

I ran either 3.70’s or 5.38’s on the street back in Brooklyn........