We recommend using these heavy duty turnbuckles on at least you front upper arms.  When running on American style board tracks, the stock upper arm turnbuckles can be a little weak and bend at the 3mm thread side.  These turnbuckles bullet-proof your front end and increase the reliability of your car quite a bit.

This package includes:

-2x M4x25 Spring Steel Turnbuckles

-2x M4 Ball Cups