98 Blazer-missing out

I recently had the fuel filter changer, spark plugs, wires and rotor cap replaced. Between 40 and 50 it stalls, misses out and acts like its going to die. Can you shed some light on where I should look for the problem?

98 has a distributor. I would have guessed that Fords all went COP by then. There is no CEL? Whether or not, I would start with scanning the via the diagnostic port. Significant misfire should yield codes. Some auto parts stores will scan for free. Write down the codes and the English or just the codes if you have to choose.