All very true,.....but if the lifters are of the JAP type,then every motor had similar dimensions,because the system was used in a SV motor as well.......so the arms are all about the same effective length.....as mentioned you can buy a complete set of newmade Indian Chief roller lifters,which would be roughly the same dimensions for about $250 US........you can also get a set of new rollers to suit Harleys,with needle bearings ,for around $40 US....Nothing on old bikes is that difficult......I once had a 4cyl Henderson crank profile cut from plate and machined ,without having any dimensions save what could be worked out from measuring the crankcase ,and drawings in old books.......the high values of restored bikes makes this possible.......the days of buying three more bikes for spares are long gone.