I noticed your epa numbers are nearly identical to mine - 2 liter Escort auto. My gearing is a little taller than yours; I'm running at 2300 rpm at 60 mph. As others have mentioned, the slower you can stand to go, the better. I noticed a consistent improvement when I went from driving 65 on the highway to 60.
As far as grill blocks go, I have my entire lower grill opening covered right now, with just a smaller upper opening left open. This is fine in the colder months, but in warmer weather I have to make an opening in the lower block to get adequate cooling. Use the temp sensor in the SG to monitor coolant temps when experimenting with grill blocks, as your stock temp gauge is likely not accurate enough to notice any changes.
As for SG calibration, one thing you have to account for is that winter fuel blends are less energy dense, and the calibration will need to be adjusted for this. I was using + 5% all summer, but as the weather has gotten colder I have had to increase that to + 8%.
__________________
|