No. Well, not easily.
The T5 has a seperate bell housing while the T45 has an built in bell housing. To replace one with the other is not a "bolt them up" job. I'm not saying its impossible, but its hard, and why would do this in the first place? The T45, despite its documented crapulence is actually stronger then a T5, which is the whole point of the T45. If your friend is looking for a stronger tranny, then stear him towards the Tremec line. There are several that will fit with only minor aches in the *** , as aposed to pains in the *** . There's a big difference!
