1984 E30 318i M10 alternator / drive belt issue

[damo318i]

hi,

im working on a E30 318i with M10 old school bosch K jetronic injection non power steering but has A/C and have been trying to replace the alternator / water pump belt. Now genuine and aftermarket list a 11A865 in Australia, but that belt is like over 100mm to short and the belt that was fitted was a 11A980 which is too long next size down is 11A965 which too small.

Now im thinking a wrong alternator must have been fitted as I can see a 2nd hand ones been put on due the black texta write stating bmw 318i 85 written on it bosch part number 0 120 469 617 and the pulley seems too be a wide v belt size similar to the a/c belt. and im thinking possibly a M10 EFI ones been fitted I know there are in a different position mounts higher up then the mechanical injected M10 is. the adjuster arm has been modified / grinded also.

wondering if anyone else has had this issue before???

Thanks for your time, Damo