So I have found some posts on similar issues but not exactly what mine does. 289 2 barrel carb... car drives fine for about 20 min at highway speed. Then starts to hestitate badly and eventually stall altogether. I have to sit on the side of the road for 3-4 min and then it starts back up and will drive again for another 5 min or so and then repeat the whole process. Other similar posts in here seem to say it happens when they get to highway speed. It in my case it only happens after having been going that speed for a while. It accelerated hard when I step on it so fuel doesn’t seem to be an issue. New ignition coil, plugs, and wires. Has an electronic ignition that wasn’t done by me so maybe that? Timing has been an ongoing source of confusion for me. When I time it to factory specs the car runs very poorly... really lumpy. The more I advanced it the better it runs. At about 25 degrees it runs super smooth but i know that’s way too advanced. Any help is greatly appreciated.