Snubber valve for electric gauge?

If you have the gauge where it is supposed to be, at the CP-3 inlet, there is no need for a snubber with any gauge.

That doesn't tell you what the pressure is where you need it and will be hard on the gauges. LP pressure needs read at the CP-3 inlet or you will never know what is actually happening. Also, putting that far away from the LP gives it the cushion need so you don't kill the sending units.

Depends if you have the OE filter in there also. A filter and 6' of line will cushion the pressure hit so it doesn't hurt the sending units. The problem with putting the gauge at the pump is it may not reflect what it is at the CP-3, and, then you want to use a snubber even with the electronic gauges because the pressure hits so hard at the pump it messes things up.