As a new 410 owner too I bought the following as a 'must have' for the pit box
RW Spur gear (no offence TD, but there's seems to shred when they get warm)
Alloy Steering arm (Either TD or Tresrey) - to replace kit part 340007 (bottom part of servo saving arm)
Steering knuckles - TD340071 (this comes with rear hubs too)
Steering top hats - TD340004 (they seem to go missing easy if the above snaps)
Front wishbones - TD330026 (just because i'd want a pair in case)
Rear GB drive shaft guide/Lipo holder - TD310039 (or Tresrey similar part)
The above are simply aimed at adding some strength to a few areas and to make sure you have spares for the bits most suseptable to breakage.
I have gone further to bullet proof some other areas including machined gears, metal rear gearboc holders left and right.
I have also blinged out mine a bit with some tresrey gear including the spring adjusting retainers as i feel they work better than plastic ones (they seem to move to easy)
GB oil wise I would start at 10k in the front, 3-5k in the rear. It's a good basis for most tracks that are in the UK. I would if you can buy a 10k, then a range of 3, 4, 5 and 6k oil. If you need a half weight you can, with care, do this by mixing 2 together. As for what it does, this is explained in post 2
