Have you ever looked at the steering rack and sway bar bushings on a bone stock 3rd gen 4runner or Tacoma? Most of them should be replaced. I've seen quite a few myself.
50psi is insane.
When gasoline goes up, so do tires. Even if they didn't, your not going to offset the cost one bit by having hard rock tires. Have fun shredding them up.

 

From every tire I've had its generally 30-35 psi street. My buddy has a Tacoma and he has newer Yoko's that are suppose to take like 45psi I beleive.

 

Some good reading in Harry Lewellyn's excellent article on "Tire Pressures for 4-Wheeling":
- http://www.4crawler.com/4x4/ForSale/...tml#Background

 

my 32x11.5 Dueler AT's have a max of 50 and i run them at 50 on the street and love it i ran them at 35-40 and got 14mpg and bumped it up to 50 and im getting 16mpg the less rolling resistance the better mileage but keep it to the tires specifications. I air down to about 20-25 off road and it handles like a champion(for AT's at least) haha