Kerch, I must profess total ignorance of I-76. I-80 I can help you with, at least a little.
My main source is a book called The Interstate Gourmet, published in 1986. A lot of the places listed are long gone, but quite a few remain. I’ve only stopped at a couple of the places listed on I-80 because it’s a toll road through both Ohio and Indiana (and Illinois for that matter, but you won’t be on it very long in Illinois). Because we’re usually trying to make good time, if we stop at all between Chicago and Cleveland, we will frequently bite the bullet and stop at one of the dreaded oases.
One exception is for The Rib Shack in Granger, Indiana, about 10 miles east of South Bend. I don’t know how long this place would be in business in Kansas City, North Carolina or Texas, but in Indiana it’s pretty darn good. From I-80, get off at exit 83, turn right at the end of the ramp and then soon turn right again onto Route 23. It’s a little more than 2.5 miles on Route 23, passing over the RR tracks. The store is on your left.
As for your time in Gurnee, the more I think about it, the more I realize your almost as close to Milwaukee as you are to Chicago. On top of which, the traffic going to Milwaukee will (normally) be a lot easier than the traffic going towards Chicago. Milwaukee is a highly underappreciated Roadfood town.
If you like Mexican, get to the corner of 5th and National. There are at least four very-good to excellent Mexican places within hopping distance of each other. Our favorites are La Perla and La Fuente, both north of National on 5th. We were at La Fuente just this past week and there was a new Cuban place, Hemingway’s Habana Vieja, right across the street. We would have eaten there but my taste buds were already locked onto La Fuente. Hemingway’s looks very cool, lot’s of dark wood fixtures including a huge bar that looks like it is going to come alive (you’ll see when you get there). Good menu, reasonable prices.
There is of course Solly’s home of the Wisconsin butter burger, discussed on many threads here a Roadfood. Do a search for details. In fact there are numerous threads on Milwaukee here. I’ve read most of them and there is enough information there to keep you eating for the whole week.
Have good trip,
Buddy