Wow, some info I would NOT follow:
I would love to see anything from Caterpillar (or any other engine maker for that matter) who recommends overfilling the crankcase by 4 quarts. Good way to "rust-proof your toad"
And the shallow vs deep sump could be had on any 3126-- the deep sump was an option. Safari was one of the few who ordered deep sumps.
Shallow sump is stamped steel (i.e. smooth and magnet will stick to it)
Deep sump is cast aluminum (ribbed) and magnet will not stick to it.
Huge difference in capacity-- you need to know which you have!
You could also call the Caterpillar RV hotline with your engine serial number to find out: 877 777-3126.