I made a similar set of alignment pucks for the 8.8 I narrowed for the Heap.  found a straight chunk of heavy wall tubing for the bar.  Worked just fine. 
Tom:  If the bearing pucks need to be different for an 8"....well, I know a guy with a couple of lathes.
 

The end pucks are made to work with both large and small bearings ends.  If I needed or wanted to I could buy new ends in either small or big bearing sizes.  I opted to just reuse the BB ends. My thought is if I end up using it or even if I sold it, that upgraded axles would be bought anyways so why not leave the BB ends on it.  On the other hand if I did use SB ends one could use their stock 8 inch axles. 

I would have made the pucks on my buddy’s lath but I’m so busy I decided to buy them. If I need to make pucks for anything else I will.  The bar I got from the local steel supply store and it was only $45.  Had I ordered one online shipping would have $60.

TKOPerformance wrote:

Its a down the road project, but eventually I'll need to either narrow the existing 8" rear, or swap in something else.  Honestly an 8.8 would be a great option.  I already have all the tools to set one up.  With 31 spline axles and the other parts I have in my '89GT rear its stronger than a run of the mill 9". 

I agree.  I fought howlie gears and an annoying vibration in the old 8" for years.  Then when we tore the car down for the "Major" I decided to try my hand at an 8.8 Explorer.  31 spline, Limited slip, disk brakes  and easy to set up.  Did the narrowing my self and with all new innards except the 3.55 gears I have $750 in it.  And with my stockish 5.0 I will likely never have to touch it again.   AND...its quiet as a mouse.

Was able to finish up the housing today.  I made it 52 inches wide instead of 52.25.   I did have issues with the pucks in the case sliding out.  So I took off the bearing caps and ran them on the flat stone I have.  That was enough to just keep those pucks in place.

Very nice work.

I have always been told to be sure the pucks/alignment rod rotate freely as all the welding is done to assure perfect alignment.

I am leaning towards Bullet’s solution if I ever work on the rear end again. It seems that a quiet 9” setup is no longer obtainable, even when you pay $200 additional for the latest design “stealth” quiet gears. I have had five sets of 9” gears in my car, all from well known and various name brand vendors. Every one made noise except the 3.0 set I bought from Phil at 9” nodular. He used to post on here, but I have been unable to locate him in the last ten years.

I remember reading years ago about how they track preped cars in the '60s, and somebody said you could only align the front end with a solid rear axle.  One of the old timers said that wasn't true.  They used to heat and quench the tubes to gain camber in the rear.  He said the splines would tolerate over 1 degree of camber at the wheel and still slip into the diff.  I wish I cold remember who it was that was being quoted, but I remember thinking that was wild.  Those guys really did whatever it took to win!

6sally6 wrote:

TKOPerformance wrote:

I remember reading years ago about how they track preped cars in the '60s, and somebody said you could only align the front end with a solid rear axle.  One of the old timers said that wasn't true.  They used to heat and quench the tubes to gain camber in the rear.  He said the splines would tolerate over 1 degree of camber at the wheel and still slip into the diff.  I wish I cold remember who it was that was being quoted, but I remember thinking that was wild.  Those guys really did whatever it took to win!

Prolly Smokey Yunick.........
6sal6
 

It wasn't Smokey.  It was one of the guys we tend to associate with Ford.  Not Shelby, but maybe Holman/Moody or someone like that. 
 

Rudi wrote:

It was Horace Oszefogva, an obscure but very innovative Hungarian automotive racer.🥸

 
I’m sure there is a comedy reference here, but I ain’t smart enough to figure it out!!

Heating and bending the rear axle may be fine on the track, but how is it on the street?  Both tire wear and bearing life could be affected.  How much does it help in any case?  When I purchased mine, it had a bent housing which had to be replaced because of a whine.

It is an interesting thought.  I might have done that once.

To clarify, we are talking about the axle tubes, not the center section where the gears go.  If that's bent its junk.  The tubes, you are talking about an incredibly small amount of misalignment.  I doubt the bearings, etc. would even know.  tire wear?  Sure, same as running additional camber on the front, but no one seems to care about that in the interest better of handling.  We are talking about adding about 1 degree of negative camber.  Honestly I never noticed much additional wear with only 1 degree. 

I have always just heated spots and sometimes heat and cool quickly. Not all tubing reacts the same.