Quote:By "stock" i mean a factory standard, unmolested engine. It matters not if it is an A12 or A14, so long as it has not been modified in any substantial way, then it qualifies as "stock"

The original carb was configured by the factory to give it's best all round performance. Changing the jetting just makes things worse in the majority of instances.
I'l go with Feral on the timing. The ignition will give it's best if you have a "dwell angle" meter with inbuilt tachometer, & a quality timing light. Set the dwell on the lower end of the specified range & recheck the timing after about 5,000k to make sure things are still where they should be.