Email Chris Birdsong [email protected] he should get back to you.Yes I have watched quite a few of Chris's videos. I don't recall him mentioning this specific measurement though. I will have to spend some time tonight and research more.
Best to not weld anything until every panel is mocked up. I'm just doing my trunk now and the factory trunk lip was atleast 1/4 inch past the rear x memeber before the steel turns up 90 degrees where the valance attaches.Thanks. For now I have installed the pan with self tappers only. I am going to wait until the rear quarters, rear valence and tailight panel go on before welding the floor in. I am thinking that this might need to all come together at the same time.