Ignition help

[toyman2]

Ok here is the deal, I think im taking out ignition boxes.
put a new one in today and fires right up like ive been running it all day, stop and start a few times on and off with no issue. it sits for a few hours and all itll do is crank like mad and sputter when i let off the key, like one cyl is fireing once.
The thing runs like a top, allthough it has been sitting for a few years.

79 ford F-250 supercab with a 429, C-6, 205.

sure like to figure it out, i want to be driving this day to day but this is a big problem.
Thank you for the help

[toyman2]

i think its the switch its self