Have 7 quart oil pan, high volume oil pump and have gone from stock Merc remote lines and 12x2 inch oil cooler, to AN10 lines and 16x2 inch cooler. Still seems its only taking about 7 quarts. While not all, it appears most of the oil drains back to the pan when motor is shut down. Wonder if any oil should be added above the fuel mark?

Will be installing a new 16x2.75 oil cooler for next season

-10 lines&your cooler don,t hold a lot of oil,less than half a quort would be my guess.

when you install your new cooler you might want to switch to -12 lines also,that is what most folks use for cooler lines.

Guess your right on not much in the oil lines.
Checked with the guy I'm working with and he says it will fill up the first time when motor is started, only a small amount will drain back. Just check as normal

normal...