Dave,
The 4 leaf asymmetric springs have their mounting eye set in the current [i.e further back] position. Your +8 is a 1996, so should have Lockheed brakes [cable operated, not rod operated handbrake] and should fit safely. However the upper shock mounting on the roll hoop may now be out of alignment and therefore need spacing, either with longer bolt and sleeving at the top or by de-centring the axle, as below.
If you have a rod operated handbrake, the revised rearward axle location WILL cause this mechanism and the fuel tank to foul. If this is the case I would suggest using Mulfab axle centring blocks mounted 'back to front' with the 4 leaf springs, effectively to de-centre the axle and win space.
A 'side effect' of fitting 4 leaf springs is that your rear shock absorbers may lock out on compression. The geometry of removing leaves is that it reduces the available space, the currently available AVOs appear have a greater compressed length that some OEM shock absorbers. The factory went through a number of iterations of rear shock absorber bottom bracket; to gain more space, to make them strong enough, etc. My own solution was as recommended by Mulfab, this was to obtain longer, replacement mounting brackets manufactured by Three Elms. A check on their website will show the before and after brackets, their replacement ones are worlds away from the OEM bracket, being double skinned and having an additional pick up point as well lowering the bottom shock absorber mounting.
