I'm stating to use an intake/exhaust of the same length, be it 5.011 or 5.025 granted some are split int exh of each, it's only .014 diff! Fwiw I don't fuss over .015 or less height diff between int and exh.
Exhaust valve have a thicker margin anyhow, so maybe that why the diff. I have never thought about it much with all the more important things in building an engine.