Hello from NH

Welcome to FABO! I'm sure you'll get some good info here.

As far as the dipstick, while maybe not exactly correct, do a full drain.....and then add 5qts. Run it a few minutes and shut her off and let it drain down. Then pull and wipe the dipstick several times. See where the level is and mark it there. Regardless of the level vs the stock mark, that should be a safe level.