Move the top rear shock mounts down the main frame. This pushes the rear wheel down too, increasing ground clearence and steering angle. The end result is that the steering head angle is the one you want, without the technical difficulties involved.
The trouble with this is that it will leave the shocks at a more extream angle to the frame. This will mean that the sprigs could well be too soft to work propperly at that angle. Welding extended shock mounts that pertrude rearwards and set lower down the main frame allows the use of your chosen shock, as the angle stays the same. Alternetively you hang the shocks from the subframe, as is done on the original twin shock bikes. The downside here is that the subframe will need to be much stronger, meaning the bike will be heavier.
Cutting and chopping the steering head brings a whole load of strength and alignment issues to the excersise, when a simple adjustment at the rear does the job better and more easily, with no reliability or longevity worries.
Of course another way round it is to simply buy a longer pair of shocks
Val.
He rebuilt the shock I put on Jills bike. Top job 
