98/75 is much larger than 92/68
think of the outside 1/8 inch of a 1 inch circle compared to the outside 1/8 inch of a .90 circle.I think if you increase the diameter of a 1" circle 1/8" you increase the area about 25%...you have leaned a very lean carb even more.
That 1406 is very lean compared to the 1405.Edelbrock supposes the 1406 with its electric choke will probably find its way on daily drivers (read fuel efficiency) and the 1405 manual choke being much richer is for racers.
..light acceleration will always lean out because the air is drawn in much quicker than the gas...expect 15. 16.5 briefly
...even though i responded i am far from an expert!