Mj is about as close as you can get.
Look at this thread, close to the same engine.
http://www.wellcraftv20.com/communit...hlight=numbers
I still haven't bothered changing to the new 17" stainless, still have the 19" stainless on it.
From what I remember, I also ran a Solas 14.8x17 AL before the posting the thread got a little higher rpms, and a couple of less mph. Keep it in the front of the boat for a spare.
Boat handles a heavy load fine with the 19" stainless, just too sorry to change it.