My torque convertor books shows this: Early 904 TF 67 and prior use a 1.55" hub on the convertor. 68 and up 904 and all 727 TF use a 1.81" hub. You have an early crank machined for an early 904TF. You could machine the crank bore at a machine shop (engine disassembly) to 1.81" if there is enough meat which I think there is. Or just hand grind as it was suggested.
