The biggest single performance improvement I saw when I was in your shoes was a good convertor. Beg, borrow, or steal a good 10" convertor. TA makes a fantastic piece that will outlast the engine, trans, and car. I ran a 12.19 with the same basic package you're working with in my truck at about the same weight as you. I ran the TA 10" convertor and 4.56 suregrip, 29x10" slicks.Dave