Good info from Comp ! Mark order or buy a "checker" or if you have Two old pushrods (long and short) you can cut them in half and thread in a stud to creat a length checker ,once you get the geonmetry right then simple measure the OAL and order accordingly , Summit usually has a good selection ,we buy from Smith Bros in Oregon ,inexpensive and custom lengths, great service! Tom
BTW I think your going to find the length needed is considerably more than .025 ,more like .250 (1/4 inch) and your right Dart doesn't put that info out there but valve train geometry should be checked on every build
