If he got the same bracket as mine it will weight 140 pounds and that motor has got to be all of 400 thats 540 off the back. I have the 175 Yamaha and it 390 pounds so we are close. 
I am not stern heavy at all!! The i/o is all of that weight, just moved out of the center. But it doesn't seem to make all that difference.
I was riding a little high but whe you trim the motor down it is perfect! 
Here are a few pic's of it in the water! O the last pic is of BS, CB they took the pic's from BS wellcraft!!
The Boss!!