Improving "sketchiness" at high speed.

[BR3W CITY]

*As my usual, this will be a long post.

So my truck has started to reach the point where "good enough" just isn't safe, and certain areas need to be shaped up. Recently I re-did a bunch of stuff including my whole heads/topend, and my truck should be in the high-11's with the driver mod (provided my mystery-meat converter doesn't eat itself).

At 70-120+, things just get a little sketchy in the front. It likes to wander a bit up , things feel a little sloppy and some vibrations don't help.

(LS powered '66, 72 front suspension stuff/PS, hydroost)
I added single adjustable Qa1's end of last year and they helped control things a bit, and I did a new outer tierod end, pitman arm and alignment a while back as well. Under most conditions, these changes have made it pretty well mannered and easy to drive, but the wander never really changed.

I do have a front swaybar, and its bushings all look decent.

The steering gear seems to have aged poorly, so I'm guessing at least some fault lies there. I don't have any form of steering stabilizer, nor any kind of pressure modifying valve on the hydroboost.

I'm also wondering if its possible that the weightloss of the inner fenders changed the load on the front springs enough to change my front alignment. I didn't think ~35lbs would do that but I could be wrong.

Other thought? Lazy balancing, mistorqued lugs, wind?