Rpm 340 Cyl heads on a 318 !

Trivia? I believe some big block Maximum wedge motors had bore notches. There were 2.14" intake valves available. Not sure if it was 413 (4.1875" bore), 426 (4.25" bore), or both versions that would have been notched.

From Mopar.com:
"The 426-III packages lasted only part-way through the 1964 model year—until the introduction of the 426 "Hemispherical Head" engine in the first months of the calendar year. However, these packages are still on the drag strips today, winning sportsman-class races year after year in tribute to the superiority of Chrysler engineering.

Parts for these desirable engines are still available from Mopar today. For example, two cylinder heads for the 1962–64 Max Wedge are available in the Mopar Performance catalogue: part no. P5007494 with 2.08" intake, 1.88" exhaust (the original dimensions); and P5249824 with 2.14" intake, 1.81" exhaust (the exhaust valve was made smaller to make room for the bigger intake)."