2.2 yokomo wheels in the correct offset for the 870C are very rare beasts, they were only produced for a very short time as the release of the Works 91 came along around the same time as 2.2s became more popular. The Works 91 geomitary is quite a bit different to the 870C hence the reason why the JC wheels won't work (front or rear) on the earlier car.
Hear is my 870C with hub conversion to allow the use of JC wheels whilst maintaining the standard width.
http://www.tamiyaclub.com/showroom_m...9251&sid=18028