keeping straight in the burnout box

[1982 SS]

The only time my Camino steps out sideways on the burnout is when the waterbox is really uneven, then it'll move to left about two feet. Its scary when you aren't expecting it, but i go into the burnout expecting it to get sideways and ready to catch it if it does step out. I've got some preload on the right upper control arm and it stays reasonably straight. And for the record, El Caminos aren't as light in the back as some say, yes lighter than a malibu, but not by much. I'd post some numbers but I can't put my hand on the sheet from when i last weighed it...