That's my biggest dilema right. Now. I'm running the stock center diff with 51t spur. I know. Mike (Over_Revo). Has told me I need to run a center spool and a smaller spur gear from a revo. Only thing is. I drag races a lot and the center diff helps my launch. I've tried 100k center diff fluid. And from a dead stop its allover the place now. I guess u can't have it all
I have also read allot about the steering issues at those speeds. It is good to damper the steering linkage so it is not too overly reactive. At those speeds any sudden tweeks can send you into a cloud of dust pretty fast. A good smooth long surface for your runs is a must. Even the smallest of pebbles has the ability to destroy your toy in the triple digit speeds.