The 348 was intended to be a low RPM, high torque medium duty truck engine- - - -never intended to be installed in passenger cars. Above 5500 RPM, the valves start to float. Then in 1957, the supercharged Ford 312 engines started eating the 283 Chevy's lunch at the drag strips. GM cast a 3-2 BBL intake, stuffed a hot cam into the 348, and shoved it into the 58's to buy a little time while they got the 327 into production. They made good anchors for big boats back then- - - -60-something years hasn't changed that much, if any. The 348's 409's and early 427's with the W valve covers all had an oddball angle between the pistons and the heads- - - - - the "combustion chamber" is actually a part of the cylinder. The only recess in the head is a tiny depression where the valves fit. The heads are notorious for getting heat cracks due to uneven cooling.
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!