I have several questions about SVO. 2001 F-250 7.3L 300000 miles

1. I have been to several web sites and located numerous bio diesel and SVO systems is there one anybody would recommend?
2. The 01 truck is puffing a little smoke out the oil fill cap will SVO or Bio Fuel make it worse and should we wait until a new motor is put in?
3. How will the injection system hold up with SVO or Bio fuels.

We have ran Bio fuel in it and runs great when it is warm outside the only thing I see is that the MPG drops.

Thank you for any responses.