Since Yellow Coach was a General Motors brand, that one is probably one of the GMC truck engines. A lot of 270's were used in military rigs during WW II, but the smaller displacement engines like the 228 and 248 look the same. The general shape of the valve cover and bellhousing also suggest "GMC". The stamped number on a machined pad behind the distributor would have begun with the engine displacement- - -"228/248/270" etc. The larger GMC engines like the 426 and 503 have the carb and exhaust on the other side.
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!