it really does depend on what you want to do with the car. if it is a daily driver i wouldnt do i big single conversion. if you are going to take it to the trak a lot then get a t-88 if its in your budget. it makes about 850 hp, maybe less, i forget. this is what i did: i got pretty much all the mods you can get to make it faster and kept the stock twins. i am now making about 485 hp w/o nos. then when my stockers go, i will do a small single upgrade. i have done an 11.6 1/4 mile w/o nos so the performance with the twins is definately there.