Valiant -64 7.25 rear spider gears do not fit

Yes, I can now confirm that this kit does not work what is somewhat strange because:
- Side gears are perfect fit to diff chassis and drive axles
- Cross pin fits to old and new gears and to diff chassis

But gears do not fit with or without washers.
I even tried to use new side gears and old spider gears, they fit but will not move freely.
At last I put old side gears in place with old and new washers to reduce free play. And then fitted old spider gears, but even this would not work. It didn't allow even two washers in place albeit there was so much play in gears. So my only choice was to put old parts back as they were. There is quite lot play in gears but at least they are all complete without visible damage.