Look for late 70's Ford F-150 and E150 vans.  The fancier ones had tilt columns.  The columns are alot longer than a Mustang column, and they have column shifter, but you can use parts from your old column to maybe eliminate the shifter part.  The length is only issue and if you are making custom fit, who cares whether you cut off 1" or 8"?  

Oh, one more thing...   The turn signal switch in those tilt columns is made out of unobtanium.  Be sure the column you retrieve has both signal catches in working condition, because you cannot buy replacements anywhere.  (If anyone knows of one, I could use an extra for my 66 F-100).

If you are looking to use a Ford F150 tilt column in an early Mustang, the only two years of the '70s a tilt was factory (optionally) installed in the trucks was 1978 & 1979. 1980 went to a column with the key in it. '78/'79 still had the key on the dash.  ...I have a tilt column for my '69 bump side Ranger that came from a '78 dent side pickup.