Offroad-Express

04 hilux any ideas,
front mount ooler air more expensive to fit more piping, or front lest piping less lag easier to fit
any help appreaciated

a front mount will give you larger gains and more benefits from fractionally more cost, something in the 450x180mm or 240x230mm size will be highly adequate for your hilux and use 2 inch piping on it.
you wont notice the lag difference unless you use a massive IC and 3 inch piping