OK, if I've got a value of 12 @ LV8 208 and 5000 rpm, that is 12º added to my base of 12º, for a total of 24º, correct?

 

Not in $165 ECUs as far as I know. They take the Spark Table value, and do math (subtract base advance) to get that value to be the actual advance.
So, a 24 in the tables (along with the correct base advance in the base advance constant) will have 24° Advance at the engine at that speed/load point. If the ECU knows that the distributor is at (for example) 6° and the tables tell it that it needs 24°, then it subtracts 6 from 24 and uses 18° advance to get 24 at the distributor.

In $6E datastream, it reports 2 spark advances, one based on used advance ignoring base advance, and one using combined advance. The combined advance is close to actual (doesn't contain knock retard if I remember correctly).

 

Well, actually, I'm using the $3A in the '302 ecu. If anyone has any ideas if that works the same, feel free to let me know

 

Keep this thread going guys, this is one of the areas where I need information in order to make correct changes to my chip. Currently I backed off the timing ($6E) in the main table to eliminate a hot weather knock. That acheived it's purpose but the car is a dog in the rpm band I made the changes in. Now that the weather is cooler I can run the orignial timing settings.

I have both the Holley and the Accel books on tuning MAP computers, but I haven't found one that will work for $6E MAF setups.... A changeover to MAP isn't going to happen for a couple of years most likely with my time and funding restraints. (California Insurance companies are making everyone with a shake roof replace them with something else, that's going to run about 12-14K unless I use asphalt shingles, that only runs $5-6K).