firestone airbags

hey guys i've got a trip comming up in a month or so and i'm going to be carrying a fair amount of weight on the back and also have a full car of people.

when i purchased my suspension i went for efs comfort springs and now i'm concerned that i am going to have a shitload of sag in the rear. i don't mind spending a bit of money to get the airbags but just have a couple of questions.

how hard are they to fit?
what are they like to use?
and the main one is does it affect the up and down travel of the suspension?... desperately want as much flex as possible and really don't want it to be affected by putting airbags in.

now basically know how they work and i'm guessing that when i've got a load on and i pump them up it will effect the flex but when i have no weight on and take them back down to the lowest psi i want all my flex back...

thanks for your help

JTR

After seeing two dual cabs looking like tip trucks because the air bags were at crazy pressures and with a huge load in the back and there was no give so the chassis bent, try to share the load with others or go really easy over any big bumps.
Mind you, in saying that, I have them in my patrol with no worries and would put them in the nav if we decide taking it on the bigger trips, but I wouldn't be putting huge pressures in them.