Boy, does my son's slant run crappy!

When it sputters,is there any smoke from the tailpipe?Is it overheating?When it sputters,does it backfire?(through the tailpipe or carb)Does the exaust smell really rich or anything like that?Me myself,I would check the ignition system first.Check the condition of your distributor cap,rotor,plug and plug wires.Also check the condition of the spark plugs.Check for the obvious first like loose wires to the distributor,cracked or leaking vacuum lines and hoses,loose parts,etc.Check your timing with the a timing light.Another thing I want to mention,I had this happen to one of my cars,ran fine until it got warm,then it started sputtering and backfiring.Turned out to be a bad Ignition Module so you may want to check your module.Also get the ignition coil checked also.Most places can test them but with some research online,you can test them out with a multimeter set to "ohms" and measure the resistance on the coils secondary and primary windings to check the resistance.If all is good with the ignition,check that your choke is open when the vehicle is warm and not stuck closed.Check your fuel pressure also and the float level inside the carb,it may also be getting too much fuel.Hope this all helps =)