I have twin 1000 SCI's. 1 1/4 pickups out the rear of the boat to feed the water pumps. has anybody used the water feed from the drives to supply water to the intercooler? Drives are Imco SCX. I'd like to try this in lieu of adding another pickup

yes that will work fine

I have the external pickup and the drive plumbed into the sea strainer. I am using the Harden Marine dual stage water pump, with one port feeding the intercooler, and the other feeding the engine.

that's the set up i have now with EFI. Because of the intercooler, back cylinders are very rich at idle due to idle fuel getting to cold. Do you have that problem?

Watch out for too high of a water pressure. I do not see a problem with doing this.

One way to help with the puddling issue is to drill and tap the rear corner of your intake above the water passage in the head and drill and tap the the cover of your inter cooler on the same side the water exits the cooler. Use a 6AN line to connect the intake to the cooler. At idle, a small amount of hot water from the engine will run backwards thru the cooler core warming it. This will help keep the fuel from puddling. As soon as you start moving, the water pressure entering the front of the inter cooler will over ride the small feed at the rear and the flow of warm water will stop going thru the core and just dump out the thru hull fittings with the rest of the cold water.

Thats why I like to plumb the intercoolers off the strainer where they are not seeing hardly any water flow at idle

I have a carb setup and haven't noticed a problem. I do have the rear of the intake drilled and relieved out to the exhaust.

that will work fine

I feed the chillers from drive pick-ups ... no water @ idle and 15 lbs @ speed . Have pressure relieve valves on strainers ... we saw 25 lbs prior to valves . No pump ... just ram pressure.