The pilot hole in the early crank measures 1.550 inches, while the later crank hole measures 1.810 inches, so the pilot on the 69 converter will measure 1.810 inches and of course will not fit in the crank hole. You'll need to have a converter made with the pilot the correct size. This is not an issue for any competent converter builder. It has been asked on this board before about machining down the pilot. The pilot is hollow and there isn't enough metal to do this. Early converters also had an 18 spline input shaft where the later ones 68 and up had a 27 spline input shaft.
The 69 904 transmission converter had the larger diameter nose. You're 67 273 has the small diameter register. It will need to be machined to the larger diameter.
Can you tell me what the register looks like. I don't know what a register is or where to look for it.
Correct sir!
