Had a 1978 SR500 (red) that my brother and I roadraced when I was a mechanic back in El Paso in the late 70s. We had punched it out to a 580. Had to get the sleeve punched out, cylinder bored to accept the bigger sleeve, and the cases machined to accept the larger liner. You could see the iron sleeve through some of the fins on the cylinder. Had the biggest cam we could find and a straight pipe ending in an open megaphone. Oh, also had a flat slide Lectron carb on it. It ended up stretching the rod and shattering the piston, breaking the rod, and the broken rod punching a hole in the bottom of the case. They didn't have any rods other than stock back in those days so it was just an accident waiting to happen.
But boy, it was fast.
Here's the only pic I have of it.