Seems more info would make a better gear decision,like is it 2x4 or 4x4 or xcab or reg.cab.A converter might be a better bang for the buck depending on what his truck is.Or a custom PCM.The best bang for the buck is a good low mile 5.7 or 6.0,some many spend $2k on mods with just bolt-ons.I may get flamed but i say save your money,add cubes then you may not need gears.

 

I would get the 4.10

 

gonzo, i agree, if you have the money, add the cubes then add the boltons. however, if your like myself, as in most of us are stuck with what we have. we can nickle and dime a intake here, a pulley there, then a gear. trust me, if i had the money, i would have a 6.0 with mods and having fun doing it.