The 348 was never intended to be a passenger car engine- - - -then the supercharged Ford 312's started beating the Chevy 283's on the drag strip in 57 and Chevy panicked. They worked up a 3-2 barrel intake and a solid lifter cam for the 348 truck engine that was in the final stages of testing and stuffed it into the 58 Impala. The engine had the cubes, but it suffered from valve float above 5500 RPM. The guys who were used to winding the 283's 6,000+ RPM were not impressed! Some of the 348/409's were modified into early 427's before the straight valve cover models came out.
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!