Latest update:
Replaced the plastic rear diff cover with a surprisingly decent alloy one sourced from Ebay.
Took a test drive post T90 washer install today. Rolls well now. One thing I was surprised about, the Victory RC pipe required me to trim part the roll cage, seemed ok during a brief test run a few weeks back. However today the pipe melted a good bit of the cage, so much so it fractured the vertical support beam. I going to just remove that section completely as it doesn't seem to do much in the first place.