It's been years ago but we drilled and tapped a flame heater into the intake manifold for one of these things though the tractor was a TD-24. Was modeled off of what Perkins used in their designs. The design is quite simple and the glow plug, and fuel valve are all in one. You run a fuel line from the final fuel filter to the glow plug assembly, and power through a fuse, relay, and pushbutton to the glow plug. Pushing the button places power onto the glow plug and as it warms opens the self contained fuel valve. After a few seconds of element warm up time, the engine is cranked over in which the engine lift pump pushes diesel fuel right onto the hot surface of the glow plug element. This will ignite readily and burn as long as the engine is cranking which supplies adequate combustion air. Once the engine fires, the power button is released and the glow plug cools closing the internal fuel valve and fuel flow from the lift pump to the glow plug ceases.
These actually work very well and if the engine will crank, it will start with this system if the fuel is not gelled. Those engines did have a nasty tendency to crack cylinder heads however, but that can be mitigated with above average radiator cleanliness and cooling system attention, along with a cooldown after use.
I'd bet you'll be hard pressed to find good usable cores for those cylinder heads these days. Need to take care of what you have.