you'd need serious ground effects or you would start floating at that kind of speed.
Im not planning on going any faster than that
Iv a half cage plenty of chasis support extra air channeling etc to keep me grounded,suspension all done etc all the gound work is taken care of.If I was wanting to go faster then yest Id need some more supporting mods,diffs,gearbox being 2,,Id prob pull engine and rebuild again so could rev to at least 9-10k but be reliable..Im happy with current set up so wont be doing that in to near future.
I nearly lost it at 260ish kmph , hit a wet patch and shimmied across the road , lucky the 4wd system pulled me out of it , though my anus was in my mouth lol