4 inch lift springs and SOA are a very tall combination and won't flex all that well, plus your spring wrap on both front and rear is gonna be a biotch to try to control.
I mentioned in your previous thread, the flatter the leaf spring the better it will flex. based soley on what you have writen above, I will try to be as clear as possible.. Really flexy suspensions are over rated. Most offroad rigs now a days that still are body on frame are built with only 2-4 inches of uptravel and probably about ~8 of down travel, this is done be using an appropriate length shackle and being aware of the shackle angle, I like to see the shackle at about 45 degrees to the frame and use a flat spring. limited up travel, but the axle will droop out nice. with limited up travel, your droop is "forced" meaning that the weight of the vehicle is being applied to the drooped axle and will help maintain traction. you mentioned you havea CJ5, a really good freind of mine has a 75 CJ5, he is SOA and uses flat stock YJ springs, the wheel base is stretched slightly, he has about 2-3" up travel and runs a 37" tire. he sits about as high as a TJ with 33's and a 4" lift. the jeep simply just works awesome. I will look for pictures of it when I get home (photobucket is blocked on work PC)