After we stripped down the bike, we noticed that there was more rake on the CB650 and when we added a set of CB550 forks, and rear shocks, the stance seemed perfect! We had originally planned on raking the bike a little but it will not be needed now.
I also am using a Benelli tank that is shaped exactly like I wanted. Another big time saver! Here is a mock up of the stance. The frame sits about 7 inches off the ground without the motor or rider.