620 diff/axle bearing questions.

[Valvebounce]

Just a few queries about my 620 rear axle.

I've had my rear axle housing sand blasted, and powder coated. 

And I've bought new rear brake shoes, wheel cylinders, and new drums. 

I felt the head had more backlash than I was comfortable with, Plus they're too low geared for the motor I've got to repower it with.

I picked up a 3.9:1 supposedly from a H230/H330. The pinion yolk flange was longer than my 620 one. So I sleeved the 620 on up to the seal ID of the cedric diff. (Mine was badly cut out where the seal ran too) 

So I'm close to throwing it all back together. And I was thinking about maybe doing to axle bearings, while the axles are out.  

I gave my haynes manual a bit of a browse last night. It's actually pretty sparse in info. 

It does talk about shimming the back plate to set the axial endloat?

I seem to recall the center which came out had like a rubbing block (?) or something in between the idler gears. I haven;t checked to see if the new center has one or not. 

the brother of a mate popped the idler gears in his 720 doing burnouts. And he fitted an H330 260C diff into it. I recall him saying that he was having some trouble with his axle flanges orbiting/flopping about. A problem new bearings didn't solve.

 

So rather than make some miserable cock up of it, I thought I'd ask you fellas what the skinny is.