Thanks guys for the input to date. I appreciate the concerns raised associated with the fork length and 17" front wheels, raised engine, etc hence the questions.
I am fairly sure that someone has detailed the installation of GSR forks - probably on this forum - in the past and I'm quite happy to learn from other peoples experiences!
Current thinking (to get over the lowered frame/engine due to shorter USD forks and smaller diameter front wheel is to have yolks fabricated that not only change he rake angle but are also 'dropped' thus minimising the problem.
Again, I stress that I am currently at the planning stage so no cost involved...........just a lot of time thinking, calculating and listening!