I have just brought a Luke harness. I knew that the factory built chassis from tiger had the holes built in but I presumed that it would be threaded to just screw the eye bolts in... How am I supposed to fit them??? The eye bolts are far too short to just fit a nut to the end and im pretty sure just a simple weld around the top would not be strong enough to with stand any kind of crash... Any ideas or soloutions that have been used before???

Mate of mine used long bolts with nylocs on the end

Either Tap them, or get longer ones!

You can buy longer eye bolts, that's what I have on mine.

Mark