Resto Corner With AMD: E-Body Back-Half Rust & Collision Repair
Any serious builder knows that a solid, straight, level foundation is absolutely necessary before any structure is built. Skip this step and it doesn’t matter how beautiful the finish materials are, eventually there will be serious problems. By the same token, any serious car builder knows that one can put the best equipment in the hands of a master painter spraying the finest materials but if the finish body work is substandard, the whole effort will be wasted.
Well, there’s one more foundational level below the body work and that is the sheet metal itself. If everything doesn’t fit as designed then the most beautiful paint ever will not hide the fact that it just doesn’t look right.
We’ve stated over and over the importance of maintaining proper reference points when replacing all the various sheet metal parts. The reason is simple: everything is interconnected and any one part out of place can cause a cascading effect through the rest of the related parts. If this pasic principle isn’t observed, it can be extremely time consuming and costly to correct by the time it becomes obvious.
Muscle Car Restorations of Chippewa Falls, WI, goes to great length to see that the surrounding parts and other reference points are not able to move out of place while the repair is being done. They even have each body checked on a frame rack to insure that it’s straight before they start.
But what if the car has been in an accident at some point? Once the shell of this ’71 ’Cuda was stripped off the body work, it became obvious that it had once endured a rather crude restoration, and it was clear that it was suffering the effects of a period collision repair. The right rear corner had been pushed forward enough to affect the package shelf and the sail panel. This meant that MCR could not trust the positioning of any of the parts that make up the back half of the car.
Having no truly reliable reference point means that MCR will have to build this one essentially from scratch. Fortunately, they have a lot of experience with these cars so they know how they are supposed to fit together. Even with their experience though, simply eyeballing it is out of the question. The answer is creating unique artificial reference points so that accurate measurements can be taken to ensure that everything is straight, level, and square. Here’s how they do it!
It may not look like it’s been hit, but remember that collision repair, especially back in the day, is only concerned with getting close enough so no one will notice. MCR sent this one to the frame rack so they know that at least the frame rails are in the right locations. They’ll use them as part of their foundation to build on.Since nothing can be trusted, all the bad parts are removed at the same time just to make it easier to move around the car. Notice the support braces that keep the known good parts in their proper place and the jig posts that were set in place using the original frame rails that will positively locate the new rails.The new frame rails (AMD part No. 895-1570-R&L, $379.99 each) are located by the jig posts and a pair of rocker panels to frame brackets that were able to be saved. Everything is clamped or sheet metal screwed in place until exact fit can be verified.This pair of original brackets not only provides a locating point, they also help to secure the rail as other parts are fitted.Once the frame rails are in place, the rear cross member (AMD part No. 870-1570, $219.99) can be positioned.The trunk floor sections (AMD part No. 800-1571, $379.99) can be placed next. Fortunately, the wheel tubs can be used to reference the floor sections but they are also checked against the rear cross member.Since the inner wheel tubs were able to be saved along with these internal brackets, the package shelf (AMD part No. 640-1570, $399.99) turns out to be pretty much a simple drop in.The top part of the quarter was left in place to help position the rear window valance (AMD part No. 960-1571-TS, $279.99) even though it can’t be completely trusted. Exact fit will be confirmed once the trunk lid is in place.The rear floor section is a fairly easy fit to the frame rails and also helps to position the trunk floor.The final check for the trunk floor and the frame rails before welding them in place is to confirm that everything is level. The rest of the quarters are also removed in preparation to installing the trunk gutter set.The trunk gutters (AMD part No. 825-1570-S, $139.99) and tail panel (AMD part No. 900-1570, $449.99) must be assembled as a unit. The fit between the gutters and the tail panel and window valance is fairly obvious. The main issue is keeping everything centered left to right.If there is secret to keeping everything straight and even, it’s the use of a self leveling laser that projects a vertical and a horizontal line onto the back end of the car. The laser must be perfectly aligned with the longitudinal axis of the car.The quarters (AMD part No. 895-1570-R&L, $599.99 each) can now be rough positioned on the car.Because the doors are known to be correct, they can be used to reference the leading edge of the quarter. This positions the quarter fore and aft and sets the height of the forward end.The horizontal beam of the laser is used to determine if the height on both sides of the tail panel is the same. This also insures that the quarters are level with each other.Left and right quarter positioning is a simple matter of measuring from the vertical laser line to the inside edge of the quarter.The final check is to bolt on the original deck lid and check all the gaps and seams. Since none of these parts are welded yet, minor adjustments can be made fairly easily until everything is perfect. The bumper will also be bolted on to insure that there are no issues with the gaps around it.
