Bear in mind that you cannot assume new parts are good, especially when dealing with cars this old. Quality is pretty much in the toilet. (When I was helping a friend with an old car the new ignition points he bought were of such terrible quality that I just cleaned up the old ones and reinstalled them.)

You are probably losing either fuel delivery or ignition. Assuming it's stock there's not much else to go wrong on a 1955 model aside from maybe a massive vacuum leak. What you might do when it stops is to see if you get anything out of the carb accelerator pump (any fuel there?), or spray some starting fluid down the carb to see if you have any ignition.

Intermittent problems can be very difficult to track down.

thanks.
the next thing i am changing is the ignition switch. i did see a tear on a wirer going to the switch..... Its no longer a vaccum issue, i think as i had a pressure gas line installed...