I have a 750F that was purchased from a friend. The rear bearings had went on the motor, so he decided to dis-assemble it. He couldn't get the screws out of the tunnel shaft, so he messed up drilling them out. As far as I can tell it probably will need a tunnel shaft, front diffuser, and bearings. This engine also has the 6 tube configuration. I had a friend tell me that the 6 tube engines are not all that good and that a mod is out there for them......anyway email me please with a ballpark figure so I will know if i want to send this engine in............like I said it is already torn down.....thanks.........Perry Herring.........email is [email protected]....hope to hear from you soon!!!