If you understood Ford history/design of their new designs started in late 50's early 60's [to replace Y, MEL, FE engines] they follow a similar approach. 221-351 Windsors and 370-420-460-514 385 series you would see that they share general design. The 335 2V heads started the cut out allowing more oil to flow into the valley. The 335 351C 4V maintained the Windsor & 385 oil head flows...
[the 351C 4V, was never part of the original Ford 335 project, it was added for many reasons ;^)]
[the 351C 4V, was never part of the original Ford 335 project, it was added for many reasons ;^)]
