2003 Chevy tracker here.
So Toyo makes a tire for the ZR2 but but not my LT
difference  seems minimal but I know these vehicles are finicky when is comes to tires & wheels.

I have always run the 215/70-15

hoping 215/75-15 will fit fine.

215/75R15 will be fine.

Just a suggestion, a quick google search will find you some reading material that will help you understand what the numbers mean, and that will help you figure it out on your own.

A 215/70R15 tire works out to 26.85 inches in diameter, a 215/70R15 is 27.7 inches or 0.85inch larger, you can go as large as perhaps 28.5 before you'll start running into trouble - it's not a hard & fast rule, there are some variables to be factored in.