The FI to carb swap is pretty straightforward and there are many different "kits" available. Most all will come with complete instructions but... The fuel injection on the 79 is fairly easy to diagnose and troubleshoot using some fairly simple tools and a comprehensive manual. The Bentley shop manual is the one I'd recommend. IMHO there really isn't any clear advantage to installing a carb in place of the FI on a stock engine. Most all of the FI components are still available, they're reliable, the system is easy to adjust and you might NOT pass smog in some states with a non stock induction system.