What would 7.562 ball and ball pushrods be from?

I have a set that measures 7.562 and figured it has to be from hydraulic lifter small block but also have a set of "KNOWN" set of hydraulic pushrods that are 7.468. Is the difference for more preload, and if so what would be the correct ones for a 68 273 with hydraulic lifters???


Thanks,

Jake