Just looking out for everybodies interests here - jizzzoe you need to make certain that the tranny is the same make, i.e. the 2001 tranny is most likely a ZF, although there are some instances reported of GM instsalls (factory freaks). The GM is not interchangeable with the ZF. They use different EGS modules and the wiring connections are different. According to records GM trannys were installed in 330CI's after 2003/03.
The reason I ask why you need a rebuilt is that I was pulling code P0741 on my tranny (ZF). The transmission felt kinda loose, and I was feeling surges occur at about 2000 rpm, it would jump up to 2400 rpm but the car wasn't going any faster. If I floored it, the kickdown would go into affect but the tranny was slow to actually put the power to the ground. I replaced the tranny with a manual. Upon inspection the only problem was that the "O" ring inside the torque converter was cracked causing the tranny fluid to bleed by the torque converter back to the transmission. My original tranny is still living in another fanatics car without any additional work.
/// Auto => 6-Spd Manual Conversion | Apex EC-7 | Koni/Ground Control Coilovers | Vorshlag Camber Plates | Meyle HD LCA | PowerFlex bushings | GruppeM rep CAI | Shark Injector | 5000k Xenarc CBI 66240 HID | BMW European MTechII | BMW Performance Shifter | ACS Mirrors and Rear Spoiler ///