[Ppb0089]

I'm doing a Hpi MT2 brushless conversion. I'm going with a MM 5700 system. I need to know witch reducer I need to buy so I can put a 5mm bore Mod 1 pinion on the motor? I did this conversion a while ago but, I was forced to sell the truck. I have a new MM system on the way but, I would like to order the pinion and reducer as soon as possible. So I need to know what reducer to buy so that a 5MM Mod 1 pinion will go on my 5700KV mamba motor? Thanks for any info.