I have a 75 sleekcraft executive that had a 455 olds and a jacuzzi yj pump. That olds has bee a pain in my ass since i got the boat so i removed that and bought a 460. it has harmin marine four point mounts. I have the motor in sitting on blocks with the drive shaft close to straight by eye. is there a specific angle or degree i need to set the motor at? how criticle is it?