High speed stability issues

My carb is not sealed to the scoop. Dialed in on an engine dyno. I'm aware of the suspension travel issues. I haven't checked the strut rods for bind, but I'm "only" going straight. My car is aligned with the requisit 1 inch extra ride height. It's all stock except for the QA1 upper arms, and the drag race alignment. I really need to take a video of the car in a few places down the track to see what the front end is doing. Not sure if my car "skated" when I let off the throttle or coasted. I have the 11.75 drilled slotted Monoco rotors with the Volare large single piston calipers in the front and 4 piston 12 inch rear Wilwood set up. 2 brake masters, and a clutch... but I don't recall when the car got unstable. I gotta say it had to be when I let up off the throttle. Probably before I hit the brakes. But I do believe it was suspension related and aerodynamics. I think a 66 Valiant is not a vehicle that does 131 mph well. I need the car to be safe.