turning the front seat support brackets around 180 degrees will give you a little more room for free.
or snyders sells 2" replacements or more expensive 6" sliders
i have the 6" sliders in one of my cars and lovem other than the price.. they also have a tilt adjustment
However I did that on my 1929 tudor and that did not solve my problem. When in first gear I could not move my foot from the break to the accelerator as my knee hit the steering wheel and was trapped by the shift lever. It turned out that the shift lever leaned slightly toward the driver's side trapping my leg. I used a little force to make it lean a little toward the passenger side. Problem solved. No more trapped knee and easy to shift.