what size did you have before?
I'm guessing you are unlifted right now, so a 2in would definitely help.
You can pick up a set of 2" universal coil spring spacers (look like rubber donuts) for less than $20, I'd try that and see how close you are.
Install them above the spring, between the spring and the perch.
I ran a set of 2" spacers like mentioned above to eliminate some inner fenderwell rub I had at full lock...I was running 33x12.5/16's though.
You may end up trimming or investing in a 3-5" lift.
edit: what year, model, etc. truck do you have?
maybe take a look at the "what hits & what fits" stickied to the top of this forum.
Are the 35s rubbing at full lock, when you hit a bump, full compression...?
If the 34s didn't rub that bad i would piece a 2" kit together.
For less than $100 you can get the coil spring spacers and some AALs (say no to blocks). You shouldn't need to change your shocks with only a 2" kit.