ball and cup pushrods size for a 360

Solid lifter pushrods are normally 1.500" while the hydraulics are around 7.25" or a little less. Ratio has no affect on required length. Some companies sell pushrods in the 7.31" range. But their use will depend on block decking and head milling. Normally they will be a bit too short or too long for optimum geometry.

The one to two threads showing underneath the rocker adjuster is a good rule of thumb. As you start threading them down and showing more threads, you actually start loosing a little actual lift.

I've never used roller lifters so I don't know if some or all brands use the same basic lengths.