Hugo, you don't really need any hopups. Just tuning parts like 2 spring kits and a set of 3 hole pistons. And don't forget your usual shock oil. That's all you really need. You can however get the optional rear aluminium hubs. Part OP687. They are 1° toe in verses the stock 2°. Plus they have 3 mounting holes with the ball stud vertical. Just look at the prototype 415 and you'll see. Stock caster blocks are 4°. I'm running the TA04 Racing ones on mine. They are 6°. I'm just testing them right now. I think that's about it really. Very nice smooth car. I love it alot!
Suradaj, I run a Monster Stock at 104/33. And I've been running a Binary at 104/32-31. You must have a small tight track for your gearing. Our track is 145x97ish. We have to complete almost 2/3 of an oval before we head into the infield part of the track. Some guys are running 6.3-6.5 final with Monsters on that track. But I've been running 6.9 and still TQ'ing. I've also just ran an Epic Roar Stock this past weekend. Kinda a cross between a Monster and a Binary. I think... I think I ran mine at 104/32. But went to 104/33 for the main. I'm gonna mess with more gearing this week. I tend to build my Monsters with RPM.
Anyways... maybe I'll try out a spool this weekend. We'll see what I can come up with for center shaft.