dont stretch the tank or you will alter the bars/seat/foot controls geometry.....in other words it would be a long reach to the bars cos you would be sitting further back
better to stretch the seat
if you stretch the swinging arm as well you are getting into an American style of customisation
if you lower it as well its a style called 'slammed'
supposed to work like a dragster......great for straight line speed, just dont try to go round corners
I went the other way and lengthened the swing arm on my mad to the max katana nice start Jim I think you will find a few knock on problems as you build it.