I was running the stock diff setup 5-7-2 and might try 5-10-3 if the track is hooked up.
I can't remember what my shock setup is exactly. 6+ months of not racing does that to me, lol.
Basicly, I think the same setup from the nitros works fine if unless you have a really heavy conversion setup. With a clean typical conversion (1512/MM) and a 4s 5000mah battery it should be close to a nitro weight.
Check the ride height, whatever your setup... it's very important with the 8ight.
Jammin CRT MM/Neu 1515 1700kv
Losi 8IGHT MM/Neu 1512 1900kv
Kyosho 777
T4 MM 5700
B4 LRP
XX4 MM 7700
old losi xxcr, MM4600 4s lipo 70mph+