Anyone know how much the dipstick tube is lacking from the contacting the bottom of the oil pan?

I only get 5 qts out sucking thru the dipstick.

Installing drain lines on the drain plugs would be a PITA, plus only change oil 1 per yr, so not a high priority.

Thinking the suction can type of oil changers that use a small hose shoved down the dip stick may be easiest, providing the smaller tube doesn't curl back up once shoved down.

The suction can types work good as long as the oil pan doesn't have any baffling to get in the way like my 420 does. Usually ends up leaving ~2 quarts of oil in the pan when I do mine. I dump that out through the drain plug. Like you said, PITA, but I only change it once a year so big deal.

The suction tube my pump is pretty stiff ....you can feel it touch bottom and would really have to force it to get it to roll up .... I put the drain hoses on my new motors (attached to the drain plug) and I plan on attaching the pump hose to the end of the drain hose and pump it out that way ....m

Once you put the drain hose on the bottom of the pan, you will wonder why you didn't do it before. No pumps needed, just run the hose out the bilge plug hole and let it drain. Plus you get 100% of the old oil out with no mess. I always found I left at least 1 quart in the motors when it was sucked out.

I agree the drain hose is best. Put one on my last boat.
Was looking tonight and the drain pan plugs are directly above a stringer with about an 1" clearance. PLus having to be able reach them to do the change over.
Can't go out the drain plug; twin engines, center stringer, 1 drain plug. Not a straight shot out. Plus 2 bilge pumps blocking the path out the back. Would have to pump it out, as offthefront mentioned.

I like this, it is on my cruiser but I think it can be installed for
$200 on any engines.
http://www.x-change-r.com/changers/changers.shtml

I installed a oil pan hose and pump it out with a Jabsco hand pump model # 340600130. I made up a hose with the fitting. It only takes a few minutes and you get all the oil out. I was having a problem oil leak and determined that the pan was overfilled because I left a few quarts in the pan each time. It is a 425HP with baffles. I was so please with the ease and simplicity that I installed another hose in my transmission so I can pump it out. It makes oil changing quick and clean. If I could only figure a way that the oil filter did not leak when loosened, it would be a pleasure changing oil.

Save a plastic bag from the grocery store. Break the fliter looses then slip the bag over the flter before spinning it off. It still leaks, but you catch 95% of the leaking oil.

I have found that cutting the top off of a gallon milk jug works too, flexible enough to get it in there, saves a big mess.

I can get a coffee can in mine, break it loose inside the coffee can, it will go in it no problem!