Swaying issues after new tires

[4RUNN!N]

Just got the Hankook Dynamic RF04 tires in a LT265/75R16 installed. While the tires were being installed, I also had them tighten my steering as it felt sloppy around city driving. So with the new tires, sloppy steering fixed, and also an alignment, I'm happy as it rides much quieter and no more steering wheel shimmy I had at 60-70 mph (probably due to unbalanced tires).

Now to the problem. At highway speeds (60+ mph), the car feels a little unstable and feels like the vehicle is swaying slightly left and right, to put it into simpler terms, it feels as if I were driving in a crosswind. At highway speeds, when I let go of the steering wheel, the wheel will kind of turn a little left, then right but only slightly. I felt that it might be the front sway bars, but during cornering it feels fine. Can someone help me with little dilemma?

 

[TRD04RUNNER]

how much psi do you have in the tires?

 

[4RUNN!N]

I haven't checkded yet, but these are Load Range E tires so they take in more air.

 

[ohio4runner4x4]

Why in the world did you put Load Range E tires on????
I think that's your problem....those "E's" are just too hard & stiff.
My bro has those on his 1 ton truck that he tows around a skid steer with.

 

[RonMAIDEN]

I have D load range and that's even a tad much for a 4Runner but not overkill. E load range will also eat up more fuel.