Nope, no difference at all (sled ran perfect before). And one (exhaust) was so tight I went the next size than what was recommended (gut feel) and it put it right in the center of the tolerance. That made me think that valve wasn't seating fully, but no scorch marks. But I am sure without the 5000 mile adjustment, damage would have been done. So even if the sled runs perfect, get the valves checked. Since I was in there, I set 4 others to the center even though they were within tolerance, barely.
Although I have never done a 660 turbo, I think that is less labor. If you look at my pictures, everything has to come off the Z1, EVEN the trunk. The frustrating part was installing the airbox back on the horns, it's like threading a needle in a thimble behind your back. You can't see what your doing and the boots are very tight. After close to 2 hours of failed attempts, I put cans in the boots to stretch them out. Too bad I didn't think of that 2 hours before.