BMW E39? throttle body 2.5L

I have a throttle body from (what I was told) an E39. I believe it was a 2.5L 5 series and it was my boneheaded move to give it a try on my 3.0L to troubleshoot some issues....guess what, it's a different inlet size than my 3.0. Supposedly it will work on a 325 (2.5L) for the E46 generation, and possibly others, just not the 3.0L. Sold as-is but was told it was fully functional when removed from the previous owner car.