well, feraligatr sits at 78 base speed so i would definitely recommend having enough to outspeed adamant versions, which are the most common. 240 evs is enough for gatr, which gives you 16 evs to put into hp to increase mamo's survivability slightly. in the long run though it probably isn't worth it considering that most other mamos will be running maximum speed. so i would say maximising your own mamo's speed makes the most sense. it also lets you tie with modest chandelure and outspeed all offensive mega blastoise.