Our club rules for this class (60'S sportcars) stipulate a commercially available plastic chassis without a pod, BWA/Dart motor, and 7.0mm wide rear tires.
I have built mine on a PCS chassis with styrene front uprights added to control the ride height, and a few other simple mods.
I have 10/15 cars for this class, and this is my quickest.
Cheers
Chris Walker


