Are the pipes a larger diameter? If so, that's why the torque is lower (my guess), as some of the scavenging efficiency would be lost. Also, if that's the case, I suppose you could repipe with 2.25" between the cats and the mufflers. Probably not worth it, though.
12 LS M6, IPF S/C, ASA GT-5 wheels, VMax PTB
1995 Mitsubishi Montero SR
1987 Dodge Raider Turbo Project
1986 Mitsubishi Montero 2.4l FI Transplant