FM,
It should be, I got 62 out of my 18' Tahiti with the same set up. One thing about Tahiti's though is they are a pretty light hull, don't know about an Avenger.
One suggestion while you have the boat completely apart for a new look, check the hook on the bottom. If it's more than about 1/4", smooth it out before painting, it could be worth a couple mph's.