I vote tru-trac, we have one in the chevelle put cars not finished, I had this discussion today as a matter of fact. I spoke with another that runs a tru-trac and he loves it. Quiet and it works great!
Biggest 9" combo with a Tru-trac is with 31-spline axles. I'll have 1100+ ft/lbs or 1800+ ft/lbs with race gas from a Twin turbo BB...those axles and posi won't take that for long, I wouldn't think. That's why I'm considering a Detroit Locker with 35-spline axles....