My 1984 F150 300 4x4 shortbed is running too rich and will not pass the emissions standards for the Utah salt lake county area. I have had it to a trusted shop and they can't solve the problem. Trusted meaning he worked on it for up to 20 hours and only charged me for the rebuild kit. If he can't fix it you don't pay for his time (OLD SCHOOL). The truck was an inheritance from a family member who had all the original emission controls removed back in the 80's. Is there is a source to tell me how to restore to the original emissions? Looks like the distributor was switched and a bunch of wires removed. The shop claims that the feedback for the carb isn't working correctly.
I really don't want to junk the old girl for many reason not the least being the sentimental value. Truck runs great and is wonderful as a around town vehicle.
HELP

 

The easiest solution is to pull the engine and replace it with a newer Ford F-series engine with all the emission controls and ECU intact, including the engine harness. Most reputable wrecking yards sell good used engines this way, and their engines usually come with a warranty. Sell the existing engine to recoup part of the expense. Simply trying to find and replace all the missing emissions equipment would you cost more time and money in the long run.