904 help

Hi,

I'm bringing this back from the dead because I'd like to make sure I'm getting accurate information and the sources on this and the slant six board have some disagreement.

My brother has a '70 Valiant that we're putting a '64 \6 into with the existing A904 auto. This means interfacing the smaller '67 & earlier crank register with the larger '68 to '77 input shaft (27 spline/0.875 dia') , requiring a custom converter. My issue is that the crank register inside diameters are reported with 4 different values:

One source:
'67-Down: 1.530 id
'68-up: 1.850 id

and another:
'67-Down: 1.565 id
'68-up: 1.815 id

So which is correct?

Also what are the correct outside diameters for the two converter snouts?

Thanks! Dave