Has anyone used the Air Helper springs in combination with the stock leaf springs in the rear? Something similar to this http://www.qualitybumper.com/suspension/ride_rite.asp#model_selection Right now, my cruiser rides almost level without the top and unloaded. Once I add the top, auxilliary tank, camping gear, etc., that will add another 600-900 lbs, and will make the rear end squat. I don't really want to add lift springs or heavier springs because that would affect the unloaded ride. I was just looking for something to help support the weight for the few times a year I will have it fully loaded. Also, I've only found applications for 79+ land cruisers. How different are they from a 75 FJ40? Seems like it would be pretty similar, any problems that I might encounter? I thought this had been covered before, but I've tried searching every combination of air spring, air shocks, air suspension, air bag, etc, and can't find anything related specifically to the 40. A few threads on the coil air bags, and some threads in the hardcore corner relating to swapping out the springs with air springs, but I can't seem to find anything specifically on helper springs.