Honestly speaking, I doubt anyone will be promoted to the LHS at 3.5 k hours. I know quite a number of guys who have been in kq for 6 years and they are yet to be promoted. I'd guess they are around 5k mark now...
I guess 3.5 k is just minimum, but not what actually happens on the ground. With seniority list and all that, it will take you perhaps 8 years, if lucky 6 years from joining to looking at your promotion.