After replacing both rear quarter panels,the valance didn't quite bolt on.Had to modify both end tabs by removing them and weld a 1/4 20 bolt to make the fit.Overall it fits pretty good.
I compared this valance to my original (single exhaust) valance and there was no more than perhaps 1/8" width difference overall. The screw holes all lined up and the backup lights fit perfectly. Sure, there's a little bit of tweaking to get it to lay flat against the rear frame member and the lower ends of the rear quarter but overall, it's a good fit.