"Race distributor". No ADVANCE?

The MSD dizzy in question has mechanical advance. Someone just locked it down. Easy to revert it, and bushings are available so you can set timing in the low teens and have full advance when you need it.
Do a quick google search on the model number and the lockdown feature. I'm sure anywhere, like summit will have the bushings you might need for your timing needs.
Being a 318, it will make a little improvement over points.