I have an 87 mustang gt and i got a complete explorer engine for 200 bucks. I using a my mustang block and going .030 over and using the gt 40p heads from the explorer as well as the intake manifold. Ive heard not to change cams because of speed density, and ive heard of people using b-303, e-303 and other cams. I have an e-303 cam laying in the garage and cant decide weather to reuse the stock cam or use the e cam. The car is going to be a weekend driver.