I bought one of those hand vacuum things and it gets all five quarts out
of my 5.7 Mercruiser in a few minutes with no mess at all, except for
the oil filter, which I can't blame on the oil changer thing. I'd buy
another if something happened to this one.

Mine doesn't have a threaded connector of any sorts, just a 1/4" plastic
tube that goes all the way down the dipstick to the bottom of the oil pan.

Capt. Jeff