Hi and welcome, Sarah.
To answer your question about "normal" numbers, we really need to know when "now" is in terms of shot time - meaning, how many hours post shot was it?
For instance the rest of what you posted would look like this:
330, Shot given (include dose - like 1u)
310, +1
230, +2
If that 74 was at +12 (evening shot time) then that is not really "normal". What it really means is that you probably need to reduce the dose. I hope you either did not give insulin or reduced the dose and/or are testing him overnight. If you have a low number (50-80), feed him. If it is 30-50 feed higher carb food (like something with gravy - or add a tsp of karo syrup to it) and keep testing. Post on Health using the 911 icon to get help.
PS - yes, people on this board are wonderful. Charlie helped to transport my Jeddie from somewhere near you across MI to Grand Rapids where they handed him off to me.