i belive that 31 10.5 15's on a unlifted hilux is normally the max , most surf owners do a bodylift and a land cruiser spring mod to run 33's but a 2+2" will do . As for the 2.4 it will run on 33's but can be a bit slugish pulling away , There is one guy on the surf site that is running 35's with a 2.4 with out too much grief.