I think Red Line HP 5w-30 would be a prime candidate here.
You'd be surprised how many engine builders don't know jack squat about oil and don't care to learn. There's one near me who recommends Rotella T4 15w-40 in everything. He's been venturing into higher rpm solid valvetrain stuff and can't figure out why he keeps eating pushrods. He absolutely refuses to accept that the oil is the issue. Rotella is god's gift to oil and there's no changing his mind.
Originally Posted by CT8
The engine has some serious mods ,I would ask the builder of the engine.