I have noticed on my 2012 PF that the rear Diff cover is an aluminum unit with cast in Finns for improved cooling. I have also noticed that some Pathys within the same design years of 05-? Do not use the same diff cover. Was there a model year change were the complete diff model was changed or just the diff cover was upgraded?
Not sure when the diff cover changed, or even if it did. But V8 and overseas diesel Pathys share the same diff as the Armada (R230), with no fins. The other versions of the 05+ (IRS) Pathy have the R200.