Use a ACT clutch & pressure plate (subaruparts.com has them)
Brian Steel has put one in his and says it handles the toqure of the 3.3 fine, I've got a cheap one in mine and it slips under hard launches.
The Subaru manuals don't use any electronics in the AWD they run 50/50, can vary a little, but it's all mechanical. you will need to hook up the Neutral safty switch to a switch on the clutch pedal and hook up the wires for your reverse lights, but that should be all the electronics you have to mess with...Oh yeah you have to bypass the column lock at the auto shifter harness too.
The 92 Legacy should have the 4:11 gears, unless it was a Turbo which would have 3:90's, you did get the matching rear diff didn't you? you can't run the SVX geared rear diff with the Legacy Geared tranny, you need to swap the Legacy's rear ring and pinion gears into the SVX rear housing to keep the LSD rear(plus use the original SVX rear Axles)
Hope This info has been helpful.
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Huck
Subaru Ambassador
92 SVX LS-Tour Magnaflow Exhaust, 5-Spd-AWD
88 XT6 AWD 5-Speed "Bride of FrankenWedge"
15 Impreza Premium Sedan
15 Crosstrek XV 5-Speed
My 5-Speed "How-To" Write-up
1976 Pontiac Firebird Formula
Current Count of Subaru's Owned.... "70"