I've got a foxbody with TeamZ k member and strange adjustable struts in the front and UPR arms and an anti roll bar in the rear with drag shocks and stock springs. When I stall it up to warm up the tires and do a burnout the back end pushes right. Diff is pretty centred left to right and in the wheel well good front to back.
Wildwood disc brakes with a spool and 9" outers on the 8.8 diff.
Looking for help on what to check or try adjusting before I screw it up more.
Thanks

 

If the rear end starts going to the right out of the water, you have too much right rear bite and you need to loosen the left front. If the car goes to the left out of the box, you have too much left rear bite and you need to tighten the left front.

 

It goes right in the water and even on the street just doing a brake stand.

 

Just because the wheels look right in the wheel wells doesn't mean the rearend is perpendicular to the centerline of the chassis. I assume the car has not been scaled properly either. The triangulated 4-link is difficult to adjust preload without getting the rearend all out of whack. Most adjust preload with the anti-roll if it is squared with chassis and still having drift issues. I like setting cars up on scales/roll-off pads while it is on my leveled up 4-post lift so it can easily at ride height with either driver or equivalent weight in the front seat, fueled up, tire pressure correct etc. All this matters. I generally put down body tape where I plumb-bob chassis points and tape down a large piece of brown paper under the rearend. Find left/right suspension points at front a d rear and mark on floor. Mark center between these. Have a friend help you pop a chalk line from front to rear across the paper you taped down. Now take a set of dividers with a Sharpie or pencil taped to the end you are going to make the arc with. Sweep an arc under the rear with one end of dividers on the centerline you marked side to side under the rearend fairly well centered. Then turn 180 degrees and sweep another arc that is on centerline and intersects the first arc as wide as possible. When you scribe a line between these two intersecting arcs it will be exactly 90 degrees/ perpendicular to the chassis centerline you popped with chalk line. Now simply drop the plumb bob(s) from front or rear edge of axle tubes as wide as possible for the best resolution to see the error with. Simply measure each side from plumb bob to the perpendicular line you scribed. Move the rearend as required to get these distances the same and the rearend will be perfectly square with the chassis. This is all based on how good your original marks are to find the centerline so please take the time to make sure these are as accurate as possible because it effects the final product. Even after all this, some high powered cars still need a little rear steer to go straight mostly due to chassis flex but this gives you the best possible starting point and most cases it's all that's needed. Hope this helps.