The new prop will no fit all the way onto the new shaft??? Anyone experience this? The prop nuts go right on.

Could be stainless on stainless, because stainless is more likely to gall up it this could be your problem... Try getting yourself a 3/4 x10 tap and run it through the prop to clean up the threads then carefully (and with anti-seize slathered on the shaft) put your prop on...

10-4 on that tap idea. I went ahead and returned it to MB. Evidently, they had a batch of props that weren't milled all of the way through. So, they finished out the threads and are sending it back. Hopefully, that's it!

I will use the anti seize when I get it back.