Biggest issue to new builders is forgetting to install the overdrive bearing on the back of the overdrive piston, or putting those bearings upside down.

Don’t forget you need to check with the special tool and select the correct overdrive shim. If the shim you need is in between two shim thicknesses, always go to the next thicker shim.

Good thing you know about the tooth angle changes between diesel and gas.

As for the shafts being replaced, you must check with the special tool to make sure you select the correct thickness shim that goes on the back of the intermediate shaft. Oil everything up, especially those needle bearings, and you should be golden.