changing diff ratio, broken LSD???

[fax0815]

Hi,
my freshly rebuild diff with TRD LSD just started to get excesive input shaft radial play. I´ve no idea whats wrong, cause it has been assembled with new bearings and solid spacer by a professional shop. Any initial ideas?
Is there something to take care of if I´m using the solid spacer?

In the meantime:
Since I need the car in 2 weeks and probably won´t be able to fix it.
I have a complete T292 Celica TA22 diffhead sitting in my garage. It´s the same spline as Zenki AE86 and the bolt pattern should be the same.
I´ve considered to weld it and use it instead of my LSD.

BUT it´s a 4,1:1 and not a 4,3:1 like the AE86.

Anyone run a 4,1 on a AE86 before, is it much different? (more top speed?)