47-55.1 Continued overheating issue

[dsraven]

not sure what your lower rad hose looks like but an actual hose, with a smooth inner surface, still has more friction loss than a steel tube would have. friction loss slows the flow and makes the pump work harder, with a pressure increase, to get a specified amount of fluid through. is it possible for you to have a section of something like exhaust tubing bent up in the shape of your rubber hose? then attach it to the rad and pump witha short section of rubber hose? just thinking the old stock water pump is not able to overcome the restriction of the long rubber hose with the 90 deg bend.
as a firefighter I have experience with water flow through fire hose. friction loss is a part of the calculation in order to get the correct nozzle pressure and water flow at the end of the hose length. each hose length has a friction loss number assigned as per inner diameter of hose and it's length. larger hose has less friction loss than smaller hose, obviously, to achieve the same amount of water flow. also, inside the fire engine body, from the actual fire pump (a centrifugal pump similar to an engine water pump) out to the hose connections on the oitside, the steel lines are said to have such negligable friction loss that they are not calculated into the pump pressure equation. even though there are 90 degree bends etc.
just a couple of thoughts, but possibly the stock water pump is unable to flow enough coolant due to the change from the stock format of hoses and rad. automotive water pumps are less "engineered" compared to a fire rated pump. also, possibly the rad tubes are not as large inner diameter as the old original rad was spec'd at. the rad can be the same size but require a better pump to flow the same amount of fluid through it due to friction loss, if that makes sense. the water pump still needs to draw coolant from the far end of the engine and drive it through the thermostat, hoses and rad, heater and hoses, etc. then, lets talk about air flow restriction, would it be possible to turn those aluminum flat bars on edge and use angle brackets to mount the fansto the crossbars? the fans and the mounts they sit on are also restrictions to air flow and disrupt air currents I would think. air needs to flow past the grill, which contributes to a disruption of air current flow, then past the other items in the way, before it can pass through the rad, which also looks to have fins that are fairly tightly spaced when compared to the stock original rad. laminar flow is what would be best, where air flows straight instead of turbulent.
possibly all these points add up to your overheating issue as well as a new engine that is now high performance compared to a bone stock factory original.