Toe-in changes when front end lifts at track

Does it come out of the water box straight? You can measure the lower ball joint grease zert to the rear axle on each side. Sometimes you can fine a 1/4 inch or more difference just in all the "lazy tolerances" of the car. I've seen some put spacer between the leaf mount and body on one side of the car to get the car to track true.
It does come out straight. But I do 3rd gear burnouts and lift as it comes out of the box. I'll have to go think back ..every now and then it will tend to turn a bit in the burnout. I think it's random which direction but I'll confirm. I've always associated that with just pushing/sliding one of the front tires.

On the street, the car seems to track straight and any "heavy accel" jaunts stay straight. I equate that to the fact that it doesn't have traction on the street. No big smoky burnouts on the street prior to launching it!! (Heck, i don't do much standing on it on the street anyway as things happen quickly on public roads. And it's a red car and it's loud and...you get the picture!)

But I think your idea is a good one to measure the left and right track just to be certain as part of this issue. I've just seen videos of the car and see that RF tire looking like it turns in and think there's something there.