The Delco has been in for several years, when I swapped out the Maganox the car acted exactly the same, ran and performed great for about 10 minutes then the misfires and spuddering began befor it shut down, if i tired to operate it, after a normal start, if I waited 10 minutes or so it would start and you can drive about a half mile. If the car cools you can drive in for about ten miles. I get the feeling something is heating up and breaking down. Only code seen is B440 which is an air issue.. No other codes.
Just replaced the harmonic balancer and new crank sensor...Everything seems great..with them.