So what 2.5" lift do you have now? Do you want to stay with 33's or upgrade? Do you want to do an SOA or stay SUA?
I raised my flares on the body as high as I could(about 1" or so) and have a 1" bl with a 2.5" lift, and 1" lift shackles. I can clear 33's easy. I run 32's to be a little easier on the d35.
Any 4" sua spring lift should clear 33's. Look at the lift review thread and see what you think.
Here is how mine sets with the mods above...