Hey there, I used the b4 arms in the back and I used the tranny height spacers to make up the difference in width of the b4 arms on the chassis side.
I found that they worked however I wanted to know what your thoughts were?
here's the track that we were running on in NY, USA.
http://www.youtube.com/watch?v=u0xIIQBozB0
this was the a main, super high traction