Grease viscosity?

I'm running a X1 CRT with 3665 2300 motor on 4s.Now temps is really high on the motor because of the front unloading to much.I only bash and don't race.I have 30k in the center diff right now and not thick enough.Will normal automotive wheel bearing grease work for time being till my 100k diff fluid comes in?And will 100k be enough?

But for now just want to know if the grease will be better than the 30k?