Here is a link to my ig post of my ftd. Diff feels great. I ran this event with everything else stock save for the diff and rear diff bushings. It is such a great feeling to have the car rotate on throttle instead of just plow through a corner. There are still some front end grip issues due to old tires and camber, but mostly old worn tires. I probably wont do anything about the tires until the real season starts.
Aside from tires, I will be doing the the suspension before the next season but I'm still undecided on the frequency I want to operate in. I read a few years back that street tires work best around 2hz but I don't know if that is still true for the current street tire offerings.