When we upgraded our throttle and shift levers, I had to move the shift cable attachment point on the transmission so it would go into gear without the lever hitting the helm guard. The quick fix was to just move the cable back in the clamp, but it is not really meant to attach like that. It work OK for a while, but when I replaced the shift and throttle cables, I decided to fix it correctly.
I made a bracket out of some spare aluminum stock I had left over from another project. I drilled holes to match up to the existing bracket on the transmission, then new holes further back for the clamp. This moves the cable back about 5/8″, which in our case was just right to all for proper adjustment and throw.
I painted the new bracket with Rustolium to help protect it.