looking to swap out hooks on my 1.5 shallow cranks. wich size do you recomend?

If the bait is over 2 inches I would use #2's & #4 's. If 2inches and under #4's & #6's.

You might as well go "all in" and replace the trebles on your KVD crank with #2 KVD Elite trebles.  Those are the best I've ever used, but they're awfully expensive if you have more than a few cranks to swap out.

I remember hearing KVD say that you can actually go a size up because of the short shank on the KVD Elite Triple Grips.

edit: I actually looked at TW and here is a quote from their description: "the shorter length of the Short Shank design also allows anglers to use larger hooks, further increasing hooking potential (i.e. you can replace a stock Size 4 hook with the KVD Size 2)"