[Mike J. CT]

I have built many of these and after leaving the cluster in the bottom/side of the case, installing the input and main shaft, installing the input bearing retainer, I tip the transmission up on it's front surface. I use a work mate so the input has clearance. I lean the transmission forward so the cluster tries to get closer to the input shaft and turn the input shaft. Now it spin the tailhousing on the case to expose the countershaft hole and stick my finger into the hole to help align the cluster. It works every time once you get the hang of it.