I am finally getting my boat delivered this weekend and i am trying to find the flushing muffs for my 300x with a sportsmaster drive. I called the local merc dealer and west marine and neither have it. Where should i go to next?

Mercury High performance has the orange muffs for either the sportmaster Bravos or the OB's, I believe there in there on-line store

we went to our local lowes store and made one out of pvc and thin rubber hose. It worked very well. i will try and take a picture. Using a pvc nipple that screws onto your hose, and attach that piece to a union which has 3-4 small nipples and then attach the thin durable hose. Once you have fabricated that piece you can then insert each small hose into the lower unit. we found it created more water pressure then the units avail for sale by mercury.

Would like to see some pics of this set-up for Bravo XR Sportmaster Lower?

We have the Imco, Bravo, Bravo Sportmaster, Merc Outboard Sportmaster in stock.

I built my own also out of a stock side entry muff set up piece of aluminum and bungie cord worked pretty well used it for a season no issues

Yea,
I bought one and it doesn't work.
The connection to the water hose is 3 inches aft of the pickup slots in my sportmaster lower unit. Even with duct tape in won't put enough water into the motor. I burned out an impeller trying to use it.