Adding a Fan Shroud

Glad to see you're building your shroud with some depth to it. Too many people put a flat piece of aluminum maybe 1/2" from the radiator with a hole in it, & wonder why they are still having cooling problems.
I cant answer about the depth of the blades in the hole, but I think you should be fine. You do want some of the blade out, my guess is to "fling" the hot air outward instead of piling all up at the block, water pump, Alt., & A/C & P.S. if so equipped.