by Kors » Tue Nov 03, 2009 1:42 am
If your Legacy has dual port exhaust heads, then in hypothesis they should screw up. The 2.2 engines did have dual port heads for a couple years I know my 95',s 2.2 was dual port, however the most of 2.2 engines are single exhaust port heads and no 2.5 headers will fit.
Unless you're upgrading your whole exhaust system, it's doubtful that putting WRX headers, presuming they fit, could make any difference in the strength of your Sube. Now, switching to unequal length aftermarket headers will give your car that distinctive Subaru boxer rumble, but it won',t do anything for power. there's one place that makes them for the 2.2 and some number of who do for the 2.5 engine.
You could add aftermarket intake/filter, a throttle body spacer, and intake manifold spacers. Possibly underdrive pulleys. And, work on the suspension a little and just make the car more fun to carve corners in.