so im guessing that my 3.0 omc is using a 400 omc sterndrive is that correct
The 4cyl used the 400. The 6cyl & 8cyl both used the 800. It's called the Stringer drive due to how the motor is mounted to the stringers and the outdrive is connected and supported entirely by the motor via the intermedieate housing. No part of the drive is mounted to the transom.
so im guessing that my 3.0 omc is using a 400 omc sterndrive is that correct
You forgot the Cobra which was the most used.