Some pushrods inside diameter changes the further down the shaft,usually the press fit area is in the first 2 inches.If your building pushrods or using unfinished kits make sure they are close to the approximate length needed.Many are high quality Chromemoly and hard to cut without special tooling.If you just need to shorten them just a little you may have a machine shop turn the shaft down just below the cup and try pressing the cup in further.If the are a premade quality rod it's almost impossible to remove the cup.It's most always cheaper to make or get the correct length set than spending the time reworking a set.