Every engine needs back pressure. You'll be fine with 2 inch pipes. Have an H Pipe, X Pipe, or Balance/Crossover Pipe installed if going duals, it'll improve scavenging and the engine will thank you for it.
Shane
Shane's Toys... 2007 Forester XT Limited (2nd Owner) 1991 Cherokee Laredo (2nd Owner) 1981 Chevy 3/4 Ton Fleetside 8,600 Camper Special (3rd Owner) 1965 Chevy 3/4 Ton Fleetside (3rd Owner)
