I don't recall older engines having the inside of the oil pan painted, but a lot of newer pans seem to be painted on the inside.

Is the new oil PH so different the pans rot from the inside out?

The reason for my wonder is this, my cummins needs a new oil pan, the road salt has eaten the outside of it. The cummins pans are like tissue paper.
The OEM cummins/Dodge pan is over 1000.00 dollars in Canada with the updated bolt kit and gasket.
The aftermarket pans are way cheaper but then there is this out there.


Long story short, the aftermarket pans have an issue the paint coming off and wrecking the motor. I am thinking to buy the aftermarket pan and strip the paint off the inside, Just wondering if I am missing some magic science on why the inside is painted. The oem pans are painted on the inside as well.
It looks like the cost difference is the paint. Should I do something like glyptol to it after stripping it?