Exterior door in Interior Jamb??
If it's a typical pre-hung interior door with a "split" jamb, I wouldn't hang an exterior door on it. The exterior jamb is stronger and will support the heavier door better. Besides the difference in hinge size, some older interior pre-hung doors only came with two hinges and an exterior would require three. (The ones I tore out of my house had only two.) A pre-hung exterior door would be easy to install, and as Bob mentioned comes with all the appropriate weatherstripping and a threshold to seal it tightly.....
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