The block casting number should be located down low on the passenger's side front, just above the oil pan rail. One surefire way to differentiate between a full pressure 235 and the early 235 and 216 engines is the "oil distributor"- - -a roughly triangular shaped sheet metal plate on the driver's side near the exhaust pipe, also just above the pan rail. It has a copper tube beside it which goes through the cooling system to the valve lifter chamber that supplies oil to the rocker arms once enough oil pressure develops to lubricate the lower end of the engine.
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!