1975 Chevy Blazer HOW TO SOLVE THE PROBLEM

1975 Chevy Blazer V8 Four Wheel Drive Automatic

HELLO PROS.I HAVE A 75 CHEVY BLAZER 350 ENGINE 4X4 HEI. IT WAS TIME FOR ME TO DO A TUNE UP ON THE BEAST. RUNNING FINE JUST TIME TO DO IT. SO I CHANGE CAP ROTOR PLUGS WIRES AIR FILTER FUEL FILTER. GET IT DONE DRIVE DOWN THE ROAD AND IT RUNS LIKE CRAP. SO I CHECK AND RECHECK THE WIRES AND FIRING ORDER ITS ALL GOOD AND STILL RUNS CRAPPY. SO I TAKE IT HOME AND CHECK IT AT NIGHT AND ITS LIKE A LIGHT SHOW. SO I FIGURE I GOT A BAD SET OF WIRES SO I GET NEW ONES AND STILL SAME PROBLEM. SO I DECIDE TO PUT OLD PLUGS CAP AND ROTOR BAK ON AND STILL THE PROBLEM EXISTS.I HAVE RUN OUT OF IDEAS AND WOULD APPRECIATE SUM HELP THNKX