Optimize the spark curve for a SlantSix.
Did you get the slow idle down to normal. Or at least normal for '73?
If this is the original distributor for the engine, what's the tag number?
Here's an example of the acceptable timing advance for a '73 225.
The initial can be set plus or minus 2.5 degrees, but it has to be at 750 rpm or less. By 800 rpm its advancing.
This only holds true for that distributor.
A distributor with a different curve will need a different initial, and end up with roughly the similar timing from 1800 rpm on up. For example a non-smog '67 distributor was set at 5* BTC at 550 rpm.
Did you replace the vacuum advance?
Did you get the slow idle down to normal. Or at least normal for '73?
If this is the original distributor for the engine, what's the tag number?
Here's an example of the acceptable timing advance for a '73 225.
The initial can be set plus or minus 2.5 degrees, but it has to be at 750 rpm or less. By 800 rpm its advancing.
This only holds true for that distributor.
A distributor with a different curve will need a different initial, and end up with roughly the similar timing from 1800 rpm on up. For example a non-smog '67 distributor was set at 5* BTC at 550 rpm.