Classic/Antique Car Repair: set timeing on 390-1969 amc, emissions standards, carburetion

Question
i checked it says to set it at TDC is this true, i have owned other amc's that were set at 5-BTDC. can you verify. 1969-390-amx-4-speed-4-barrel

Answer
TDC is correct. In 1968 new emissions standards were put into effect. The only way the makers could get the cars to meet the standards was to retard the timing and lean out the carburetion. In the trade we called it the "lean and ;ate" period of auto design.
Brad