Need help with wheel size!
 

I have a 99 Blazer LS 4X4 4dr, and I'm trying to find some new wheels for it, but I don't know what the backspacing is. All I know is the diameter (15'') and the bolt pattern (5-4.5). What would the backspacing be? Also, what would the wheel size be? 15x8 or 15x10? My tire size is P235/70R15. I am looking at ProComp Rockcrawler wheels like these.

Series 97, 15x8 with 5 on 4.5 Bolt Pattern - Gloss Black

ur wheels should be a 15x7 with a bolt pattern of 5 on 4.75. but i could be wrong. backspacing should b sumwhere around 3.5". but im not 100% sure.

Stock wheels are 15x7, 6" backspacing, bolt pattern of 5x4.75.

Straying from stock specs means higher chance of rubbing. Going to a 15x8 with 4.5" backspacing means the tires are going to stick out 2" further than stock and could rub on the fender and/or bumper while turning.

Yeah you don't want 5x4.5 spacing you want 5x4.75! 6" is stock and the most you will find in the pro comps I believe is 4.5". This will work but like Jam said you increase your chances of rubbing. Also get a 15x7 with the tire size you want to run or your rim will be to wide for the tire and it will look funny.

could i just use these with my stock tires right now then get another set later?

Series 98 Rock Crawler - Gloss Black Monster Mod Wheel

Yup, those are the ones you want. I don't know about tires clearing though. Someone else may have better insight into that.

Why would you get another set later?

I meant set of tires not wheels