Bill McKee wrote:
My Autolite had the tag on one of the top bolts. Is a marine carb, not an
automotive carb. Differences are that the vent tubes on top are J tubes, so
the stuck float pors the fuel down the carb throat, and the throttle shaft
has some flats and grooves to prevent leakage out the shaft.

Then show me the Autolite "marine carb" that has a model number of
300RS!!!!!