[CO6.7Cummins]

I wouldn't waste your time if that's all you have done to it... auto or manual? definately launch it in 4wd

Actually, I think its a great time to race it. Racing it near stock will help judge the effectiveness of his future modifications.

Back to the original question - launch in 4 Hi. Since your transmission is stock, don't get too crazy with the launching. Sitting there doing a boosted launch builds heat in the transmission - and heat kills transmissions.

This may seem obvious, but I'll say it anyway. After you are done racing, and before you make the turn back to the staging area, put it back in 2 wheel drive. Turning in 4 wheel drive on dry pavement isn't something you want to do.