Thanks for all the responses!

Maybe I confused the issue a bit by asking how high I can go without problems as I'm really not interested in jacking the truck way up. Just a couple inches would be fine, though it seems most kits are 3" lifts.

So here's my situation, maybe you guys can help some more. I just bought this truck and the springs are shot. I spend a lot of time driving, several hours a day usually, so a good ride is important. offroad capability is not so important as 95% of my driving will be on the streets of Seattle or on the freeways. This truck will also be used to take me up to the passes in the winter to go skiing and for traveling on old, washed out logging roads in the summer to get to hiking or fishing spots. I'm also on a really tight budget so may be willing to compromise a little bit on ride quality just to get something that's better than what I have now for a reasonable price. I've read about building your own springs but frankly I don't have the time to go scouring junkyards and then experimenting with putting the springs together to come up with the right combination. I really need a bolt-in solution.

How about just getting some stock replacement type springs and putting add-a-leafs in them?

I realize my expectations may be unreasonable, but if I don't ask, how will I know? Thanks!