There's only one thing you need to know about them: They are not worth messing with. I got so tired of messing with mine, I swapped it out for a Motorcraft 2100. It was ten times better. But still not as good as my fuel injection, which is ten times better then the 2100. I wish I would have just went that route to begin with.
A rebuilt stock carb works pretty good. Easy and cheep to rebuild yourself, easy to adjust. They are not a bad carb..... But the 2100 is better Mine took a little tweeking to get it adjusted but it was not a bad swap.
possibly they did the "nutter bypass" where they take the computer control out of the loop and help it run better. Search for that and see if that makes sense with the current wiring