Question about the fuel distributor. Most places list the fuel distributor as Bosch 0-438-100-109. Mine is Bosch 0-438-100-105. Are these 2 interchangeable? Or did a previous owner change the 109 for the 105? Another question about the FD. The frequency value large connection is connected to the FD at the fuel input hose (from fuel filter). The diagrams I've seen show it connecting to the fuel return hose. Is this wrong and I should move it from input to return connector? Thanks