Dry Plate Conversion on Film Pack Adapter

Trying to convert a 3x4 Film Pack Adapter to be used with Dry Plates.
Took a 3x4 standard film holder and measured the distance from the external wood edge to an old exposed sheet of film and got about 4 mm.
Is this correct?
Does anyone have an old Film Pack they can measure?
Of course would have to deduct the thickness of the dark slide bottom side of the case, before we made an insert to set the emulsion side of the dry plate at the correct height. .
Thanks p.

Film surface from the edge of the holder is .197 inch ± .007 inch for 2x3, 3x4, and 4x5 film holders.
Converted that's 5.0038mm ± .1778mm .
Is this what you are measuring???

Yes.. thank you.. will give it a try with some paste board and see what happens.

Anyone out there tried this, and if so any suggestions ..

What plate holders does the camera take ? I assume you mean Quarter plate 3¼"x4¼".

Ian

Yes Quarter plate..