Late to this conversation᠁.
Delco d1959 is the module part number in my Langdon.
When I bought my dizzy from Tom in 2021? ( it was very near the last he made) and installed it I had a hard stumble during acceleration, I chased my tail checking and rechecking everything again and again for weeks including reinstalling the orig points dizzy to confirm it ran as before (with the new wires and plugs).
For lack of ideas (and desperation) I bought and installed a new OEM Delco D 1959 module. The stumble was GONE, truck ran and has run better than it ever had since.
I immediately looked to buy another OEM module but could not find another. From time to time I search for that part and have yet to find a real one ᠁.just other brands᠁ didn’t realize how lucky that purchase was᠁..
I bought but have not tried an off brand module, might be worth testing᠁ if I had time᠁.
And I keep that points dizzy on the shelf᠁..
Chuck
