There is lead to melt out at the roof pillar, the bottom of the roof gutter and the quarter to rocker transition. Grind out the small welds at the rocker to quarter, at roof seam and brass brazing at the upper trunk gutter. Drill out all the spot welds down the trunk gutter, to the deck fill panel, down into window corners and up the inside rear window opening before the transition, roof to quarter, inner quarter support, in the jam, rocker to quarter transition, inner rocker to quarter supports, wheel wells, quarter to extensions, quarter to fill panel and rear cross member and you'll be set...Take the time to check out the restoration threads. There is a ton of reference pic's and posts that address the removal/installation of quarters on 68-70 B-Bodies.