My 99 cdt, a quad cab, short bed, automatic was to say the least had very poor performance(bone stock 100kmiles)when i first picked it up. I was very disapointed(real bad....[sm=lame.gif]). So after doing some reading, i decided to do minor improvments, intake filter, silencer ring(mostly for my pleasure), and exhaust. After ordering all the parts.. putting them on all at the same time. let me tell you, simply night and day. i'm extreamly pleased. k&n high flow filter (with extra holes drilled in stock box for more air), silencer ring removed (again for my entertainment), and mbrp stainless 4" turbo back. All i know is i'm really happy withthe add ons and the way it turned out... used to jump in and out of od, now she could care less, and from my point of view, the mileage has gone way up...about 2 or 3mpg.

 

Get a tune...then you'll really talk about night and day

 

right on... another mod to consider is the ATS intake manifold... I think they make one for your motor being a 99,

http://www.atsdiesel.com/ATSWebsite/...InManifold.asp

have this on my truck and it gave me a nice low end boost, noticeable by the butt dyno & the wallet (check mpg thread in sig for details)