The twin SUs will tend to have a sligtly wider powerband/useful rpm range, and (properly eetup/specced to suit the motor) better throttle response, so the actual performance advantage is higher than any peak power number difference might suggest.

well i guess i'll keep my eyes peeled for some SU's. If i can find them cheap enough I might pounce on it. Right now I have a problem with the rear end (which I think is a pinion bearing) and the tie rod on the passenger side. I've thought of buying a new rear end since I've heard that even installing a turbo to the stock motor can break the axles, not to mention a disc brake upgrade would be nice. The problem is, I have had little to no success finding a compatible rear end in the states. The stock diff that's in it now is a replacement from the original which had shredded spider gears. ugh