I would really recommend that you check out http://lorenzindustries.com/ , http://thecarlisuspension.com/ and http://thurenfabrication.com/home.html before going with the blocks. THe blocks are inexpensive but I think in the long run you would be happier with one of the other suspensions.Lorenz claims you can run 35's with his springs in the front. I had for a while on one of my Dodge's and really liked them. I have been going to put them on my 94, but my 33's cler fine.
I am looking forward to seeing pictures of your truck when it is done.