[Oldsguy]

Was that 24 bdtc with or without the vaccum attached? Make sure the vaccum advance is disconnected and plugged and try to bring down the timing by steps, say 5 degrees a step. After bringing down the timing the first time, then re-adjust the idle misture screws. The car may be way out of adjustement and it might have been done on purpose to cover a problem, especially since is smokes. You might be right about the cam not being dialed in correctly. At any rate, trying small steps when something is way out could work, I think 10 or 12 btdc is more correct for a stock engine. Then again, if the engine was rebuilt and there is a non-stock cam in it then the stock tune up figures won't necessarily apply. But whatever the case, it shouldn't smoke.