The shroud looks good, tip clearance is a bit more than I would have done, however it should improve air flow. There are three things in a cooling system. Air Flow, Coolant Flow, Surface Area.
your shroud will have helped the air flow.
Having the radiator checked will verify the surface area. If you find a blockage, may correct coolant flow. If not, you have something amiss with the water pump or engine itself.
The fact that the engine is overheating within 1-2 miles has me concerned. Running a vehicle without a water pump turning would allow you to do that before the coolant temp increased enough to boil. (My Sister-in-law's personal best is 6 miles down the road before the engine overheated due to a broken a belt).
Are you sure the water pump you have is good? Is the thermostat working properly?