A spray-oiler 235 from 1951 will probably have a short side cover over the pushrods which does not extend over the side of the cylinder head. That was only a 2-3 year production run, and those heads are as scarce as a chicken with lips! It's possible to install a 1954/55 235 or 261 that will be virtually a drop-in fit, or modify the splash oiler 235 to have full pressure oiling, and 270 cubic inches without making any obvious changes to the external appearance 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!