Trying to find wheels and tires to fit on my stock 2003 4x4 blazer. 17" or 18". I know a 30" tires should be good. 5x4 3/4 bolt pattern and a 6" backspacing. what about offset? is offset the same as back spacing?

 

No, they are not the same. Offset is the distance from the center of the rim to the wheel mounting surface while back spacing is the distance from the back of the rim to the wheel mounting surface.

 

Look into Camaro/Firebird or C5 Corvette rims to find what you are looking for, though you may have to run a spacer as some of them are a bit over 6" of backspacing.

 

if you change the offset the backspacing has to change right?

 

If the rim width stays the same, yes.

 

so if you have 6" backspacing then the offset will always be the same. im confused.

 

Go to TireRack.com and search for backspacing and/or offset. They have a complete description with a picture to explain it. Heck, you can search here as well. I know I have posted the picture before as well...

This should explain things better: