engine misfire?

[72WiscSub]

1972 Suburban - 350 engine, auto tranny. I did a tune up the other day, replaced plugs, wires, distributor cap, rotor, coil, condenser. The engine ran a bit rough before so I wanted to tune up because I was not sure what the PO had done. Some of the spark plug wires were pretty rough.

After installing all parts the engine started fine, and ran smoother. That was two days ago. This morning I take the Burb out and it runs fine. Went to do some errands, and was cruising around for 1/2 an hour with no problems. I did notice just a little hitch in the idle once and a while buy nothing to noticeable. Well tonight the wife and I went out for dinner (16th anniversary) and on the way to the restaurant no problems. When I got in to come home and pulled out of the parking lot the Burb all of a sudden it seems like the engine is misfiring, it hesitates on acceleration and it has a slight popping noise. When at cruising (30-35 mph) it seems fine, but when I take off from a start it hesitates again and pops. Funny thing is it is not all the time.

Also, before tune up the engine started great, turn the key and bam, starts right up. Since tune up the engine cranks a few times and starts then quits. Pump peddle a few times and starts but I get a little puff of smoke from the exhaust.

I am pretty new to this engine stuff and wondering if anyone has any ideas what is causing this. Is it the new Dist. cap or rotor?

Just frustrating that it ran better with no problems besides a bit of a rough idle, before tune up.

Look forward to your feedback.

Thanks