If your gonna keep the rev's to 5500 then do what mother mopar recomends. the orange box. They work just fine. The other boxes were designed for higher rpm's and not recomended for constant running. I've been useing them for years and never had a problem. I just ordered a new one from Summit for my GTX. As stated above Crane,MSD fine for bragging right's but don't do any better on the street.