Ideally you need the shifter handle to be centered pretty much dead center in the shifter hole. I used the Competition Plus console shifter, but not the wrap around mounting bracket 3734529 (which was in this Z when I bought it), along with a 661 fine splined '70 model Muncie close ratio 4 spd and a Lakewood blow proof bellhousing. It had the same problem of interference on the 3-4 side, the whole mess was dealt with by scrapping the shifter mount, changing back to a '68 660 cased close ratio Muncie (car was equipped that way to start), 403 bellhousing, and using a Hurst 1957773 mount as pictured, which approximates the '69 shifter mount dimensionally. Using a salvaged Muncie handle carefully cut to position in the same location as the original Muncie shifter, you can see the front-to-back and side-to-side position of the Hurst and the handle, which is in neutral in these pics (uncut original console-equipped floor, documented Z). Add your boot, console and appropriate handle, and it takes a more than close look to see if it's live, or Memorex. If you don't remember the old ads, whether it's a Muncie or Hurst rowing stick.
By the way, the handle location is slightly canted to allow for shifting into reverse. Hurst thought of that - I didn't have to. Also, you can usually find these mounts at a good price on eBay. I think the 3734529 mount places the shifter a little low in the tunnel, maybe causing the handle to rub too far right. Just my opinion - it works for me.
Regards,
Steve
