Why high resolution Crank Position Sensor?

I am looking at converting a old 1960s International 4 cylinder engine to EFI (spark and fuel). It is based on the 88-91 GM TBI-Throttle body injection system. In the conversion there is no crank positions sensor, but there is the adaptation of the "small cap GM EST" distributor onto the International distributor. I am guessing that the GM distributor provides a TDC signal. But I expect it is a single position sensor.

How do these GM units get accurate spark and fuel timing with such a simple signal? Or maybe I should: why bother with a high resolution crank position sensor?

thanks for the enlightenment.

Ref: https://www.binderplanet.com/forums/index.php?threads/parts-needed-for-the-gm-conversion.45292/

OK, from what I understand from the link provided, that was for converting the installed EFI fitted as OEM on later model vehicles to GM parts - possibly for reliability or parts availability. I don't see it being directly related to your application.

In context, it looks like the distributor options given were for those wishing to use a distributor rather than an individual coil, or wasted spark, coil conversion.

As you pointed out, there is no mention of crankshaft position sensor(s), or many others that may be used - there are several different timing disc options on the market which can be fitted to the front pulley, with pickups, and you should be able to find one to adapt for the engine. The distributor conversion mentioned may have a pick-up for identifying the crank's firing or overlap rotation, but if not you can batch fir the injectors, or if using a GM TB, some use the body as the injection point.

Not something I have experience of, so perhaps some more knowledgeable people can better advise?