RE: .28 in a funfactor? oh dear....
Here is what I've got so far. Power Racing Swift CVJ's, nuckles, and the associated hardware.
The Swift CVJ's are approximately 1mm longer that the stock CEN CVD's and the pillow balls will screw into the CEN arms with some effort. So far every thing is lining up ok with one exception, diff cups. I modified the Swift cups to fit in the CEN diff but the cups a 12mm in diameter versus the CEN's 10mm. They are also considerably longer. So the arms have very limited movement and they would be to weak if I clearanced them.
What I need to do is find a diff cup that I can use that will allow full movement of the arms with minimal clearancing that the Swift shafts will fit in.
The reason that I am going this route is so I can use Romulins without the hex adapters and have a choice in buggy wheels and widening options.
It might even be possible to use Ofna shafts and nuckles but the same diff cup problem will have to be sorted out.
When I have it sorted out I will try to get pics and write some clearer details of the process.
rolland