I'm not sure if I would call it "inadequate" just yet, considering that I most likely don't even have the right thermostat and most likely am missing the stock restrictor plate. After reading some of the other references, apparently having the heater hose circuit opened up and bleeding heat through the heater core is doing what it's supposed to in the absence of a non-functioning bypass circuit.
I haven't had much luck with electric fans on other vehicles I've owned, so I currently have a monster 7-blade big-block clutch fan that fits the correct shroud & standard [for an H-Code] radiator, but everything is new. I might have to play with timing a bit, but right now it's set at 16* BTDC (non-vacuum setting) and running strong with great throttle response. I'm thinking that if the problem persists once I get the thermostat/restrictor plate situation squared away, then I'll definitely be looking into a better cooler solution.