Good question Dan! I e read up from several sources and this is what I have learned. The answer can be a simple yes BUT it is not always that simple. Let’s start with the valve itself.
A 1.88 vs a 2.02. The larger valve will flow better everywhere.
Why?
The diameter of the valve has more area in which the air and fuel can pass on by into the cylinder. But……
That’s just the valve itself. Let’s just assume the valve job is done at the best advantageous angles and the valve is set in its seat at the perfect placement height. If the bowl area under the valve is t sized and/or ported to it’s best size, the valve will not flow it’s best.
When you take out a 1.88 valve and install a 2.02 without any work under the valve, the gain is very small, just a slight improvement at best. The gained curtain area isn’t maximized. It’s kind of a waste of a mod at this point. Also it’s why a factory 2.02 head is a more or a prize head over a 1.88 head or the same casting.