locating perfect shifter rod length

[bricktron]

i read that some hard (manual) shifting can be caused by a shift rod of slightly wrong length. i have hard shifting into 2nd and always blamed it on a worn synchro, but now i wonder if the rod length is also to blame. would this problem be associated with the 2-4 rod being too long or too short? is there any way to get the adjustment right the first time?