They are different to the standard size. Not sure of the sizes but look at the pics
standard size (note the external diameter of the bearings in the cups)
![](http://www.radbmx.co.uk/archive/albums/y91/frosty_paul/DSCF1016.jpg)
versus this 400 set
![](http://www.radbmx.co.uk/archive/albums/y91/frosty_paul/redline3s.jpg)
I'm sure someone will know what the sizes are etc, but if you are after a set then give Biagio a call he made up some reproduction spindles and bearing sets for the 400 series cranks.
Paul