servo saver tightness? and another set up question.

[Nigel]

i was putting together the servo housing and i noticed it dose not say how tight to screw this




how tight should it be?

and one more question.




is this a good very low traction set up?
http://www.petitrc.com/setup/durango...ts20100416.pdf

but it seems to be mostly a stock set-up tho.

because the track i race on is a dirt/clay track with bits of gravel in some areas and is not kept at all so its very low traction.