Some of the transmission discussions suggest you should have something like a super diff starting at about 100-120 hp or so. Also recommended are the afternmarket aluminum side cover(s).
If you are planning on doing any burnouts I would think you need the Superdiff and the side cover on the load side of the transmission, just my thinking. If you are not doing burn outs, not auto crossing, not road racing, and drive a bit conservative on the road, I suspect you will be OK for a long time.