@PPS-RC which unit do I need to run the 4985SL-1650KV? There’s a couple options on your site...
I honestly do not know the spacing for most motors. But it does boil down to 2 sizes 99.995% of the time. 25mm, or 30mm. The factory screw spacing is 25mm.
It boils down to this, Would that motor bolt to the stock mount? If YES, you need the 25mm. If NO, you need the 30mm.
The 30mm is usually used on motors over 50mm in diameter.