Mercury 225HP 2.4L counter rotating

[trionfale61]

I own a Mercury 1980 225HP 2.4L engine model No 1225620 (Serial No 05977120) extra-long shaft normal rotation.
What spare parts should I buy to make it counter rotating?
Is there any kit to make this change?

[boats.net]

You would have to change to a left hand gearcase but I don't see a left hand gearcase listed for that motor.

[trionfale61]

Thank you for replying to me.
You are right, I should buy a entirely new “counter rotating lower unit”.
However that's extremely expensive.
My plan is to change selected components of the lower unit of one of the two 225HP 2.4L engines that I own which are both right hand.
I understand there is not a “conversion kit”.
As alternative, I am looking for the parts list of the left hand lower unit so that I can compare it with the normal rotating lower unit list and to extract what components I should buy to make the conversion. Can you help me?

[boats.net]

I have never tried it and not sure you could without changing housing. The prop shaft , gears, bearing housing, shims and bearings are all different.