First---you need to address advance curve of your dist and the intial/total timing------the vacume needs to be hooked up and on fords they use the port off the venture of the carb---not manifold--- total timing on fords over the years was around 38 btdc but with todays gas probably 36---------the centrifugal is slow to come in and needs to be modified, the vacume is critical to economy and cruising response-
Your issues with oily plugs on one end of a head and lean on the other is because of intake manifold/cylinder head fit up-------could be a combo of 2 or 3 things--------poor manifold, poor heads, uneven tightening during install???????anyway, its sucking air at one end and
oil from the valley at the other end-------
You didn't mention if the block was bored/honed for the new pistons??????????