tire recommendation

My 97 blazer 4 door has 235 70 15s. What is the advantage or disadvantage in using the 75 series instead. also some time sites say it would be alright to put a passenger or minivan tire like the Michelin X radial on the truck. I have those on my lumina and like them, but can they really go on the blazer??

If you change the tire size, you will have to get your speedometer recalibrated for the new tire or your speedo will be out a bit.

Also, best not going to a passenger tire on a SUV. You can get SUV tires that are passenger rated.