GP recommends .61 to .91 two strokes for the Big Stik 60. The 1.00 is almost exactly the same size as a .61/.91 and weight is also very similar. I wouldn't hesitate to use the 1.00 on the Big Stik.

Hangar 9 recommends .61 to 1.00 for the Ultra Stick 60.

The only reason GP doesn't recommend a 1.00 for anything is because OS & Super Tigre do not make a 1.00