'97 Transmission Question

I have a '97 Venture. Recently I noticed that after the car has warmed up the transmission will sometimes "hang" when shifting between 2nd and 3rd. It's fine when its cold, but once it warms up it sometimes feels like it's not going to go fully into 3rd gear after the shift. I'm afraid something has worn out inside and I'm going to have to replace the tranny. I found a used tranny on Ebay that came out of a 2000 Grand Prix and has trans. code BR. The guy says it fits the Venture. Does anybody know if this is true?

Thanks.

first of all check ( clean it) your MAF ( Mass Airflow Sensor). see other posts.
hope it helps