Go to www.aaarims.com they have all the info you need on that rim, just put in your trucks info in the fields and scroll down untill you see your rim, all the backspace info is listed right next to the pic of yor ZQ8 rim
Thanks for the info-- I still need the backspace measurement, the site only had the offset measurement, I have older Belltech spindles and 15x8 wheels with 4" backspace now with 1/8" clearance to the tie rod end, will the 16x8 ZQ8 clear??