What is happening here is that the two sensors in question are most likely from two different manufacturers, but still functionally equivalent. ACDELCO is no longer tied to a specific manufacturer like in the old days. This is due to GM divesting the ACDELCO division back in the late 90s. The part with the AC stamped into was made in the original manufacturing plant when ACDELCO was part of GM. The other one that looks different is coming from another manufacturer that was not part of the GM empire.

Warren

 

Personally, I thought the design of the sensor had changed, and that there were still some of the older design in the pipeline. That was just an assumption.

http://info.rockauto.com/ACDelco/Detail.html?AFS75.jpg

http://www.rmsautoparts.com/proddetail.php?prod=AFS75

 

Could be true. I bought mine just over a year ago and it still had the "turbine" head, not the holes.

 

The last ones I bought were also the "older" design, but it's been well over a year. It seems like a lot of people have been getting the sensor with the holes the last year or so.

 

THNX fellas for info
I'll install it