Holes that big everywhere will definitely drop your oil pressure. I'd suggest threading the inside of a fitting on one of the flex lines, and experimenting with Holley carburetor jets until you find one that gets the pressure up where you want it while still providing enough flow for good filtering. I'd suggest a jet with about a 1/16" hole in it.
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!
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