Yes; you might still ned to shim.

Installing a longer Slave Cylinder Rod will only push the Piston deeper into the Salve Cylinder Housing. Ain't gonna help.

I would suggest that you replace the Fork and Pivot Ball and shim it; yep you will need to pull that Tranny out. I like to use a good old Washer that is about 0.100" (little thiner that 1/16") or about 1mm ish. You can confirm that the Tranny is properly shimmed by installing only 4 of the Tranny Bolts when you put the Tranny back in then inspect the Fork position inside the Window. Remove the Tranny and re-shim if need be.

I would alos suggest that you replace both the Master and Slave Cylinder with OEM. Aftermarket ones might work but your chance of a good results are better with OEM.

All in all it is no fun but take your time and do not cut any corners and you'll be gett'n that Tranny to shift like butter!!!

Ghislain