Left is a standard RH rotation pump showing the White arrows Diam at 98mm. the red flow gap 7mm is too small. The std impeller has 8 vanes.
Next one has been modified White Diam is 115mm. Yellow has been machined down to top of seal depth and diam increased to widen the flow gap to 18mm. The impeller for this pump has 3 vanes, and pumps nearly three quarters as much more volume and pressure, than std.
Third one is a High Output 110LT/ min genuine GM pump for 6.5 & 6.2 reverse rotation Serpentine belt drive.
As for air flow under the bonnet I tried everything known to man, including removing the bonnet . It simply does not alter the engine temperature.My orriginal 6.2 with a 5 staggered core and an Isuzu large bottom tank, in snow country hills would over heat. The air scoop I built ,directs air up to the bottom of the radiator changed it to the extent the fan cuts in about half the amount of times. The radiator is biggest single thing to control heat, with water flow and pressure next. The other thing that the 3 cores do is to allow the air to circulate around them better, and the extra row per inch supplies another 3 extra cores.
The best one I have found is where I described it earlier on, 3 rows 16mm x 2mm 4 rows per inch and more fins. The Nat Rad core can be fitted to any 4wd. Check your water pressure , this modified one pumps 30lbs and up, easily at about 2500 revs with the thermostat closed.It cruises at 18lbs at 2000 revs (at 100kph, Turbo 700 R4 locked up ) at normal opperating temp 85C.. Brunswick Diesel dont use modified pumps as the cost is added to the install, they use the double thermostat housing, which increases the flow but not the pressure. Check your EGTemp , for over fueling.. Les