Normal oil level is about 1/3 full — many just fill until the oil fill run out when a fill hole is at about the 4 o’clock position.

Will it last at a 5 to 1 gear, that all depends on allot of factors, the most important being how high will the slip be ? The lower the slip, the better chance you have of it lasting — another major factor is how consistent the engine output is — the clutch is quite stupid, it only does what the engine tells it to do — if the power drops, the clutch will slip less — also, the cooler the operating temperature is, the more the consistency will be improved