904/727 torque converter spline counts

Yes that's true. If you'll re-read my post you'll note that I said the snout (the part that slips into the transmission) not the pilot (the part that slips into the crank). The snout was indeed a different size between 727 and 904 all through the run of both transmissions
My Bad! did not register in my little pea brain - the "snout" on a 727 is 1.872 - 1.875, on a 904, 1.495 - 1.498! Yes!!! Good way to tell! Cheech14