when i first did a zetec and type 9 conversion on my mk2 i used the rally design single piece prop and kept knocking the uj's out so i changed to the one retro ford sell and haven't had any problems since, i also used a 4.1 diff to to start with and that was plenty quick enough off the line but there wasn't enough top end for me so i changed back to a 3.89 which i found to be a nice ratio, still quick enough off the line to beat most things and would do about 145 mph. i also run a quaife atb and its great for the road and general messing about just took a little getting used to when i wanted to go sideways, i invested in some 2 piece half shafts when i snapped one of the standard ones at pod a couple of years back, but according to what ive heard about the atb they effectively go open diff when a wheel is cocked (dont quote me on this as i don't understand them) but i was able to drive home with one broken shaft cut down to stop it catching the bit still in the diff.