ziggy

i just added the triple dog to my 04 cummins and am loving it. I would like to boost a bit more (say maybe 50-70 horses). I'm running crazy larry, so the bully dog is maxed out. I'm wondering how much I could get with changing to a cool air intake of some sort and changin my 3.5" downpipe to 4" (its an 04 pre, so 3.5" out the motor, then 4" through muffler and out).

Also, are there any other cheap mods that will give me some pep without completely killing my mpg?

thanks in advance