Can someone tell me the difference between the 72-74 2.0 injectors and the 75-76 2.0 [expensive] injectors?

I have a guess, but it's based on pretty tenuous information....

number codes is the difference IIRC

What does that mean? What's a number code? You mean a part number? The part numbers are different, is that the only thing????

I believe they are supposed to flow just a hair more (or is it less?), but I know guys who have swapped them or even run the two different injectors with no ill effects.