Is there a reason for the modification? As long as the main and cam bearing clearances are correct, a regular 216 oil pump will keep the engine lubricated. I have adapted an oil pump for a Chevy 250 6 cylinder to 216 and 235 engines, but that's for a special application where the standard pump probably won't supply sufficient oil volume for the highly modified engine I'm building. If a 216 will maintain 15 PSI of oil pressure at highway speed, it will run about 3 days past forever. It's not uncommon for a 216 to show NO oil pressure at hot idle with no problems.
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!