The 235 timing gear has a shoulder that sets the end play correctly without any extra spacing being done. When we assembled John's 261 with a new timing gear set about a year ago, I checked that dimension with a depth micrometer, so I'm not just guessing. The 194/230/250 engines require that feeler gauge procedure, I believe. Also, although the cam thrust plate for the 250 looks like one for a 235/261, it's a different thickness. Don't try to swap those parts.
Jerry