Rick,I myself would go with 330s and castor mounds--total submersion of 330's ,does not lessen the effectiveness of this set.
If you are going with foothold,run slideires to the deepest water available, shorten the trap chain as much as possible and go for a front foot catch.
You can also dig out the spot you place the deep water stake for your slidewire,this can give you more drowning depth.
Now you know why I quit footholding beaver over a decade ago. I can make 330s work in a few inches or several feet of water,without all the messing arounsd --using footholds causes.
Either way--good luck and keep us posted.
Tom