68 292 single barrel carb problems

[Kapote]

OK so i have a 68 C20, it has the 292 factory motor, also has a rochester single barrel, not the unijet, the older one, and im having problems with it. Ive gone throught it twice, 1st time cuz it sat for 20 years before i got it, and now i recently did again after the winter tring to make it run right, it runs super rich, and pulses sometimes when at low rpm, makes for a not so smooth ride. im not sure the problem, any suggestions or is my timing off? what should my timing be set at with the 292 6 cyl?