I need help identifying this portion under my truck where the cab meets the bushing. It’s all rotted out and it is starting to get spongy. I’d like to possibly take it out and replace. It seems as if it’s just spot welded to the floor pan. I looked all over and couldn’t figure out the specific name/ part number for it. If anyone could help it would be greatly appreciated! My truck is a 99 Chevy Silverado regular cab. This picture is of the rear driver side of the cab almost directly under the driver seat!