Best motor length / kv for 8T

[medusa'd maxx]

I am doing a brushless conversion on an 8t 1.0 and I'm
going to use a medusa I use a 36 80 1600kv in my Emaxx on 6s which runs fine but for some reason seems toheat up my ESC - motor stays about 150F
ESC (MMM V3) has hit 170F

Im looking for a cool setup on 4 or 5 cells I'll be using a MMM again and I'm looking at doing some racing as well as some fast grass running (short to med length)
should I stick with the 80mm can? Ive been thinking 5S with a 2200 or 1600
any people out there tried this set up