That oil pan is definitely a military thing- - - -none of the 235's that were paired up with Powerglide transmissions from 1950 forward had anything anything like that. They did have "235" stamped into the pan in big numbers to prevent a mismatch with a 216 oil pan. The measurements for checking rod dipper and oil pan trough position were definitely different, and required the use of a different checking fixture.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!