What if?

For years there were published reports of a '67 273 head with an odd intake valve size (2658920 – 1967, 273 LA-series small-block, 1.88/1.50 valves A Guide To Mopar V8 Cylinder Head And Block Casting Numbers--never seen one, never heard of one measured like that out there, never found a 1.88 valve in any pre 68 340 parts books). It was a typo that was repeated everywhere. I asked a guy who had one (D-Dart) and he said the valves were stock diameter. Even the D-Dart TSB never called out different valves but did mention you could put small hemi intake valves in there from a 331 or something.