My memories of one-way diffs are;
R1 broken front driveshaft
R2 broken other front driveshaft
R3 broken transmission
R4 broken everything as you drive like a donkey as you can't get anything with just one round anyway.
On top of that there is the cost issue;
£60 for the one-way diff
£12.50 for the Shiny CVDs (so they stand some chance of lasting)
£5 for the springs to keep the outdrives in the one-way unit
£77.50 is a hell of a lot to throw at an 'upgrade' that may not suit me.
If the BJ4 does require a front one-way diff to make it work then I guess it's going to see big changes (or an Ebay listing).
Richard, thanks for the offer of help. If I am at the indoor finals with the BJ4 I'll take you up on that kind offer.
Time is running out however as I have to get a 2wd somewhere close before the start of teh season too.....