So, I have installed the new VN alternator and as with most jobs it took longer than expected with some fiddly extra work required so I�ll finalize the thread with the info.
1.When I first physically mounted the alternator I discovered the main pivot mounting, where the long bolt goes, wasn�t cast as wide as the old unit so I had to use washers to make up the gap (see picture below).

2. I found the other opposite mounting hole on the adjuster end wasn�t threaded. The hole was larger the old alternators 7/16� bolt so I tapped a new 3/8� thread and found a new bolt to suite. However the new 3/8� bolt was a tight fit on the slider but still worked.
3. The new alternators charging post was 8mm so I had to find and new nut for that.
Also had to re terminate the charging wire with an 8mm loop connecter as the original one was way smaller.
4. I found due to position the alternator sat, the regulators connector fowled onto the splash panel when final fan belt tension was applied. But I was able to bend the panel away by hand giving an acceptable amount of clearance again.(see picture below)

5. Had to run new wire directly to battery for the regulators �S�=sence terminal.
I didn�t fuse this wire as the diagram showed a direct connection.
Started car and tested a rock steady 14.4volts at battery, even at idle. The sense wire must be working. Its going to be unusual driving around with volt gauge stuck in one position(high) after 25 years of seeing them go up and down.
Another advantage of this regulator is that the dash illumination won�t dim down at idle due to the steady 14.4volts.
I also realised engine noise was quieter. Seems the old alternator had developed a noisy bearing too. Worked out well in the end.
Thanks for the help.