How durable is the 9-bolt series 2 positive traction unit and isn't there a spacer ring to allow the use of series 3 ring and pinion gears?

The unit looks much smaller than the series 3 I removed several months ago and now that the 10-bolt went south I may want to keep this 9-bolt behind the tpi as I have decided to put the lt1/t56 in another Camao. I need a little more gear than the 2.77...ya know.

I plan to use an lt4 hotcam, shorty headers and some degree of induction work magnitude to be determined.