Get the weight of the rear half of the truck with everything you plan to keep in there, i.e. spares, fuel cell, whatever. If you go through Deaver, Jeff can help you out they are real nice people. Setup how high you want it, if you plan on towing anything. I'd go through them they can even set you up with nationals.
with toyotas, we can definitely help you out.
here are your options-
prerunner pack- we take your main leaf and build a the rest of the pack with our plate. this gets you a mild increase in travel, and a much better, more progressive ride.
race pack- we build you a set of 62" springs. you get a lot of travel out of these suckers. they can get up to 22" of travel, with a trick setup, but the norm is 16-19. for these you need to fab up a new front mount, rear mount, a longer shackle, and shock mounts.
whatever you decide you want to do, deaver can definitely accomodate you.
i also recommend you talk to brett and King shocks. they can get you the shocks you need, and get them setup up right. (714) 530-8701
talk to jeff at (714) 542-3703
or you can email me at firstname.lastname@example.org"]email@example.com[/url]