Would different tires help?

[85 K5]

My Blazer chases ruts in the freeways. Sometimes it's scary, especially on Houston freeways. I've done everything I can think of. Took it to a frame shop, they tracked it straight. Said it wasn't bad in the first place. It's been aligned, ball joints, tie rod ends, drag link ends are all ok or new and the front wheel bearings are new and correctly adjusted. There is no play in the steering shaft (out of column). Spring u-bolts are tight. New steering gearbox that is tight. (Performance Steering Components)

I am running a 2.5 inch lift, blocks in back and 33X12.50 BFG AT KO's. Do ya'll think different tires would help, and if so which ones? I am even considering back to stock height and tires, but it looks good like it is. I think more of a highway tread, but should I go with 33X10.50 or 9.50 or go to the 32X11.50? I am afraid the wheel wells would look naked with 31's.