I installed new Monroe MA704 air shocks today. I used independent lines for each shock and eliminated at least 2 possible leak points by doing it this way not to mention the other benefit that was discussed. There were 2 factory holes in the tail pan that I used to mount the schrader valves. I used 55psi to get my car sitting right. Every point got a good dose of ant seize. Now to see how long they last and how much maintenance will be required. eventually I will get new or beef up the springs on the car. I like these air shocks better than the unsightly and more rough riding helper springs that I ran for a while. Thank you, everyone, for your experiences/perspectives!