I'm guessing you have not mounted the livewell yet?
With a scupper drain problem, you are just increasing the problem with the added weight of the livewell being full. [8.2lbs per gal for saltwater]
Move the livewell farther foward.
I don't like the idea of using the scpper's as a pick up.
It's a "tacky" install. [Is that easy enough on you?] HeHe
Livewell pump's have been used as washdown pump's, but they are lousy. A livewell pump is designed to push. A washdown pump is designed to lift. [disphram pump]
If you will look at all these pix's of my install, it work's VERY well and is safe, with the Seacock's installed where thruhull's are, unstead of ballvalve's.
No connecting and disconnecting of hose's and crap like that. There is to much going on, on a boat when fishing to have to worry about that stuff.
You want to turn a switch on and it work's. Turn a switch off and it stop's.
This is the bildge with the seacock's installed. 3/4in intake with bronze scoop and 1 1/2in drain out the transom.
Here is the dualport livewell pump. The top port goes to the livewell and the bottom port goes to the washdown pump.
Here is the washdown pump. It then flow's out to the washdown station [squiggy hose]
There is a ON/OFF push/pull switch mounted under the washboard beside the washdown station to turn the washdown pump on. This eliminate's having to run foward to the console to turn the pump on. It right there at your fingertip's when you pull the hose out.
Plumbing installed.
Livewell is a Kodiak 42-2. It has no exposed hose's on deck. It plumb's thru the bottom for a clean install.
That hatch is nick named a NASA hatch and it is the cat's ass. No leak's to the bildge, easy access to the bildge, no working thru leaking piehole's.
Sure it's more work to do a install like this, but look at the outcome. Clean and easy to use. No education required to train your fishing buddies as to what to hook to what. Less crap to worry about and safe. When the boat get's left in the water. Just close 2 seacock's that are easiely accesable thru the NASA hatch.