The twist from butt rib to the measuring rib is supposed to be around 2 1/2 degrees, and can be measured with a Smart Level. I had computed 2.6 degrees using the angle of incidence + that 3/8" block.
When the wing is on saw horses, you need a 1.4" block, for the stock setting.
Most Cubs I have measured have more like 1 to 1 1/2 degrees of twist. They fly just fine, and the stall seems docile without any dropping wings. I can detect no increase in cruise speed, although there must be some slight improvement. My Decathlon has zero wash, and stalls just fine.
I get into serious trouble when I use the terms "wash in" and "wash-out". I don't even care . . .
