Sorry this thread has been quiet lately, I've been busy pushing things forward with this project and continuing my testing. Been enjoying the 13/16" Bore unit in my 08' GT500 immensely and can click off 1-2 shifts at 6500 under boost even with the squishy oem shifter reinstalled in the car so the increased fluid flow definitely does the trick. Also completely gone is the stiffness going into first or reverse when cold that I was getting before and can still engage 1st or R even with the clutch not right to the floor so it's had the intended effect. Daily driving and low rpm shifts it's smooth as butter with only a half depress of the clutch pedal and zero notch from the shifter, just slides right in. So quite happy with the results thus far in testing.
Here's a few update photos of what I've been working on. The top mounting blocks for these cylinders have been sent out to be done on a local shop's CNC as well as the new adjustable 1-pc Billet Aluminum Rod Ends I had made for the project. The rod ends also get a press fit high load bronze bearing custom machined to match the stud on the factory pedal arm with zero slop/lash. Photo of the finished cylinder is the 13/16" Bore unit currently installed in my car along with a few photos of it bolted up to the factory pedal assembly. Now that I've had my factory pedal out a few times I can disconnect everything, pull the whole pedal unit out, replace the cylinder, reinstall the pedal unit and bleed the system in about 30 mins flat so it's a pretty straight forward install.