My 2 cents on head oil restricting ... when using a HV oil pump i'd suggest loading retrictors in the heads as there is way to much oil pumped up into the rocker assembly & head valley with the stock dia oil feed hole.... flooding the heads with excess oil , and @ higher RPM not leaving much oil in the stock type pans this can cause oil starvation of ther pump / it sucks air & we all know what that can lead too..... instantly .... wipped out bearings
I use .090th oil restrictors on my street builds with no issues to date....
O'll Skool trick i learned.........
A long time ago i was @ a car show in Ohio.. talking to some of the older hardcore Ford boys there and checking out there cars and there engines in there cars. Well i was talking about oil retrictors in FE engines with this fellow who'd been building Ford power longer then i'd been on the planet @ that time.. anyway i asking him about a friends 428 we've been working on with cam swap in intake changes & loading a HV oil pump in the engine.. the engine ran great ... but sometimes @ high RPM's go'n through the gears we'd see the oil pressure drop low then swing back up to normal,,,, we were sucking the pan dry.
I asked him what we could do to stop it .... buy a big race pan and trick pickup? ...He said well if the engines up & running in the car... what i do is take an old SB CHEVY hollow pushrod & cut both the end off prox 3/4 inch.long .. deburr the cut ends and wash'em it good.
Take the rocker assemblies off the heads find the oil feed holes in the heads now load the cut off push rod ends with the ball end facing UP towards the rocker shaft & drop them in the holes and reload the rocker shafts... this will restrict oil to your rocker shafts and you good to go..
I've done this o;ll trick many times and it worked for me...
Regards Daryl