Difference between 69370 and 69375 calibres?

Hi, i am a proud owner of a Rudolf Caracciola Inge Chronograph. While the non-limitd series was released, I noticed a few differences between the first limited run and the the Ingeniuer Chrono series.... namely, the difference in thickness (15.2 vs. 14.9) as well as the change in Calibre from 69370 to 69375. I was curious as to what this difference is and if it's the reason for the slightly narrower profile?

Hello and welcome to the forum. It is a little curious that the cases differ - I notice that the non-limited Ingenieur Chronograph is listed as .3 mm larger in diameter as well as having .3 mm less height than your Rudolph Caracciola. Also, the Ingenieur Chrono is rated to 12 bar rather than just 6. The only difference I see in the movements (just a quick look) is the different rotors, although I don't know that this would require a different caliber designation so there may well be other changes.

Thanks a lot Ben, i didn't notice the difference in the rotor or the depth rating. Curious as to why that was the case. Anyways, love the watch! Thanks