4 Cylinder Springs in the REAR and front with 90/10 Lakewoods will help get you the 60ft. times you are looking for. Remember, the rear needs to compress the suspenssion more than the front needs to rise, plus the weight transfer is much easier down than up on either end. I have run 4 cyl. in the rear with great success as well as many other 11 sec stangs I race with. Just my $.02