I see Chris hasn't read the box either. lol

 

Hmmm, good to know...just did a quick search and found this same info on an ebay listing from the vendor that I bought mine from...wish I could remember which one I have, I'll bet that I have the 47391 Thanks for the info Chris



*EDIT*...found an old pic of my cooler on top of the box in my photobucket page, and I can clearly see the numbers "391" on the box...eh, I'll be driving my Blazer mostly in the winter. Guess that I should have paid better attention and done more research before I bought my cooler.

 

4739 and 47391 are the same low pressure drop design. The coolers are exactly the same part. The cold weather bypass is external.

 

So the 39 comes with an external bypass, and the 391 doesn't? The coolers are the same? Well that makes me feel better, and answers the question I asked you in my PM

Sorry about the thread hijack...