Auto Racing: Handeling, loose components, top cars

Question
I race a Grand American Modified on a paved high bank quarter mile oval, The car handled great and was a consistent top 5 but a lack in horsepower kept the top cars  out of reach. So I added the Horsepower adjusted the setup but the car is all over the place what am I missing ?

Answer
that's a pretty huge question.  Let's start off with the baseline and then email me and we'll continue.  Make sure your car is square, that is all 4 tires are pointing straight ahead and the same distance each side front to back.  Then, check your toe (both tires pointing ahead), camber and caster, look for bent parts and loose components, especially your tie rods.  Be sure no brakes are binding up when hot.  Be sure your wheels aren't bent, tires don't have broken belts or abnormally worn. Next if all is OK and/or you correct problems, describe for me what the car is doing, or not doing.  Does it happen on the straighaway, going into or coming out of the corners?  Describe it in detail in any way you can, and we'll tackle the problem OK?