um, ahem....did youse guys realize that Scooby ATs have 4.44 rear diffs?
hint hint...switch out the final drive R&P in your Brighton gearbox (or better yet, swap the R&P in an RS or Forester 5MT box w/closer ratios) , and presto, you gots a rally box with super short gears that really wake up the car. it'll be buzzy on the highway, but hey we're talking project car here. you can source the shorter R&P gears at rallispec.com
to get stock viscous LSD in 4.44 ratio, just find yourself a wrecked Forester S/Leggy Ltd w/automatic.