904-273 LA Bell housing/Torque conv/ Ring Gear questions

They are internally balanced like the 318/340. The nose that goes into the back of the crank should be measured and compared to the crank being used.

Now I’m a bit fuzzy on when where and what changed but I can say, I was given these instructions as well on my wife’s ‘67 Cuda with her 904. It seems to have the newer front on the converter but the older odd spline count. This made getting a converter a royal PIA until I had ProTorque work on the OE unit and they did a great custom job on it.