Hi Bill,
I checked the military manual to see if it had more information on servicing and it really doesn't. What I do is put the main gear on a set of grease plates so the gear can move easier. With the struts serviced with hydraulic fluid, put nitrogen in while having someone gently rock the aircraft at the wing tip. It will take almost 1000 psi of nitrogen to raise the aircraft. If you over inflate, you can open the valve a bit and let some nitrogen out but be careful as it happens fast! 3.88" to 4.00" is a good reference point but more importantly is is having the wing tips at the same height. I either measure them to the ground or since I'm short, I add three fingers to my height. After many years of operation and probably a few "adjustments" to the cabin structure, the 3.88-4.00" might or might not work. The tail strut takes a lot less pressure. Jim