Is it carb time??
 

I've done the basics, test equiptment says all should be fine. I've got bright blue spark, timing at 8btdc, idle rpm @ 750 in park. Put it in gear, no problem. Step on gas, big time hesitation. I've changed filter and sprayed gumout, seems to have helped some but lots of black remain.
Thanks to Cal69chevy (who provide a most excellent carb site), I was able to determine I have a 79 4-bbl Q-Jet. If I gotta rebuild, not a problem. Just would like to get the engine runnin like it should.