There was a thread not to long ago on this. There were all kinds of responses to it, based on geographic locations. It was interesting to see the differences as to what everyone had available and what needed to be done for each type of soils.
Anyway, #2 is what we use here too for a base. That is followed by 354, might be 357?, but it is a mix of different size fines that lock the #2 in place. Otherwise the big rock always works it way up, but that might be regional thing here because of the frost cycles. Then top dress it with #57. Not saying this right for you, but what is done up in my area. I like to let the #2 be driven on till it starts packing before following up with anything. Then you can see if there is a soft spot that needs a bit more before applying finish coats.
I think the biggest/important step to take, is make sure all top soil is scraped away. If you don't, that stuff will just work it's way into your gravel and ruin it in no time.
