I was just relaying that 3/16 transfers vacuum better than 5/16 whether you use gravity or from a mechanical source. The source of the vacuum in this case is the mainline and what size lateral will transfer the vac better to the tap hole in this situation. The strive for 5 in 5/16 is do to the fact that longer runs with more taps do not transfer the vac as efficiently as shorter runs with less taps. This is less of a problem with 3/16. My experience and opinion in this situation is that the 3/16 will transfer more vac to the end tap hole than 5/16 would.