That’s weird, i had no issues using dicky mounts, i’m not sure how wide are the abec style pulleys, maybe that’s your issue.
Here are the mounts with 3dservisas pulley and tb110, i ended up using the sk3 for something else, but they did fit here, the mounts haven’t moved since i removed the motors. There is quite a bit of space left on the axle.
Pulleys are some riptide abec style pulleys. I dont trust them but its more for me to see if they fit with 12mm pulleys. Now ill be ordering better pulleys.