2004 Bonneville SE transmission swap

Greetings to all from South Louisiana.

Here's the skinny - I had the transmission in my 2000 Impala rebuilt about 8 months ago. My daughter then proceeded to total the car via a front end collision (no injuries,whew!). Engine, tranny, etc were fine but the front end was smashed.

I believe the transmission in my 2004 Bonneville is on its way out. What I'd like to know is that if I do get confirmation that the transmission needs to be rebuilt, can I have the one from the impala installed in the bonneville? The only difference I can see is that impala transmission is an M15 (245 mm [9.6 in] torque converter) and the bonneville is an MN3 (258 mm [10.2 in] torque converter). The gear ratios are all the same, so will the difference in the torque converter sizes matter if the entire transmission is swapped?

Thanks in advance for any help.