Which Neu motor with 5S and Quark 125

[Patrick]

Luvsrc is your motor the finned version? If it is, did you have to grind the fins or modify anything else to get the 16t pinion to fit?
Were you using revo diffs in yours? If you were, then 18t pinion with buggy gears (what GrorrilaMaxx360 said he's using) would be almost the same ratio as revo diffs and 16t pinion.

There is a 65t that will fit the strobe with a bit of modifying (I'm not sure exactly how much, I haven't had to do it), but you'll probably also have to extend the adjustment slot in the stock motor plate, because it puts the motor so far away. I think that spur is for a ofna pirate, but I'd check with someone else first, like Mike and I think squeeforever knows as well.