Hello there,
I'm plenty satisfied of my HF, still pretty stock.
I did the 4.6 mod but it didn't go as good as I expected, after the 3rd tank, the piston blocked into the sleeve...I don't get it...after 3 tanks...It had to explode bij the first tank if I screwed up the engine with the mod.
Wel, I put a new Nosram RS-28rs with 15t clutchbell and my friend, all I can say is that there is no comparison possible ! That thing flies !!!!

Otherwise, I just put 10.000 ofna in center diff and RB metal airfilter and rear wing mount.
ps

: I love it ! (even I won't race it)