I wouldn't worry about beating your brother, just set a goal and reach it. There is a ton you could do to your truck to make it faster. I don't think anyone gets to where they want to be in one step so plan to take a few. You could start with beating a stock L. Then work up to a modded L and so on. I have a bunch of money in mine and I'm sure I can't beat all L's.
2006 Superior Blue Trailblazer SS AWD, Stock as a rock
Sold: 2002 GMC Sportside Denali front end with a 2002 LS1, FLT level 5, Yank 2600, Trick Turbo, T76, Nelson intercooler, 60LB injectors, Warbro fuel pump, Eaton locker, Magnaflow, 3.42, Nelson Performance Tuning (speed density).
Sold: 1981 GMC LB RC 1500 2002 4.8L 4L60E 12 bolt 3.73 Richmond Lock Right AC PS Nelson Performance tuning