I used a 5 gallon portable air tank, bought from Home Depot. I cut it in half, welded a plate between the two halfs, and connected it with a 1/4" air line to each half, with a tee going to each air spring. I have now used 1/2" air line, which seems to give a little better ride. I have found that the Kelderman system is very sensitive to what kind of shocks you use. I had gas shocks on at first, and then tried good old cheap fluid types.....the fluid is smoother than gas charged shocks.
The ping tanks are well worth the effort.
Feel free to e-mail me if I can help any.
2000 F650 XLT Crewcab
, Custom RV bed, 230/660 Cat, 7 speed overdrive, 4:88 gears, air brakes, air ride suspension,air ride seats, cruise, CD player, custom leather interior.