How to Install a Full Floor Replacement in a Chevelleby Bobby R. Goldsmith
The Chevelle remains one of the most revered muscle cars in the Chevrolet line, though the ravages of time and the elements have often not been kind. Due to a rather blatant design flaw, most of the vehicles that rolled off of GM assembly lines in the 1960s with the Chevy brand suffered massive leakage during rain storms, allowing pools of water to collect in both the trunk pan and the floor pan, under the carpeting. Usually, the first step in any Chevelle restoration involves repairing or replacing its floor pan. This can be accomplished with the proper tools, experience with welding and with the proper assistance.
Remove existing floor pan completely by cutting it away from the chassis. Be sure to leave enough of the existing floor pan lips to overlap with the new floor pan, all the way around.
Examine the remaining metal for any sign of rust or corrosion. Sand or grind any remaining rust with the angle grinder.
Place the new floor pan into place, with help, and align it with the remaining overlap. Look to ensure that the new floor pan is in the proper position, that there are no gaps, and that every part of it lines up.
Tack the floor pan into place with a series of spot welds place eight-to-12 inches apart, around the perimeter of the floor pan. Place your tacks on both the interior and exterior sides of the floor pan.
Check to ensure that the floor pan is still in place, that there are no gaps, and that it is still aligned. Weld the floor pan into place along the seams.