Billet wheel backspacing

OK, I read the whole thread (http://www.streetsourcemag.com/forum/topic.aspx?method=reply&topic_id=77052&forum_id=23&forum_title=&M=False&S=True) and from what I understand I will need a 7" backspacing on a 8.5" wheel for 2wd sheetmetal with drop spindles. I plan on ordering some 20" devious titans within the next few weeks and just want to make sure that I have all the right info. THANKS

Anybody?

that's what works for me,in the front.