Outbacks and GTs had 4.11 final drive. Brighton, base and L models had 3.90.
The speed sensor gears are calibrated to match the final drive and tire size. A 3.90 (L) final drive with outback size tires the speedometer will read slow.
A 4.11 final drive from an outback with L tires will read fast.
A 4.11 final drive from a GT with L tires may be slightly fast.
If you swap to a 4.11 FDR trans from an outback you need to swap to the larger outback sized tire to keep the speedometer accurate.
The larger tires may also require outback struts for spring perch clearance.
4.11 trans from a GT will not require the taller struts.
Edited by Fairtax4me, 05 March 2013 - 12:02 AM.