I am sold on getting rid of my Sierra and getting a Sierra diesel. Info please. I need to know some termnology on the site and go fast mods. I love the idea of going 12sec 1/4 mile times or better. I just need to know how to do it. I just hope to be able to sell my truck.

depends on what year truck you get some need more then others to get to 12sec you getting a crewcab, single? you WILL need a built tranny. lift pump, efi live or ppe hot+2et tuner. and some more mods but i certainly dont have a 12 sec truck i just know of people that have 12 sec trucks run at least that.

2008 GMC extended cab or crew, have not decided yet. 2wheel drive. I going with the lowered looked. I hope this doesn't upset anyone. What is a lift pump? What does it do? What kind of tranny mods are needed? Or does it have to be a complete rebuild of the trans.

Hello Jus1975 and welcome to Dieselplace. There is more in on all these go fast goodies than you think here. Grab a comfortable chair and find the search button up in the top right. All these questions you asked are already covered many times over. You'll find just what you need and then some.
Once again welcome, Yaz

yes there is a ton of info on this forum about gm diesels. Search around and ask questions.