we have exhausted every alternative from fattening up the the carb to take power away, slowing down idle, retarding the timing 2 degrees... all that did was delay the point to where the tires spin. this is the same cam from our "big motor" which is why we think its the cam. we put this combo together to mimmick the 604 crate. which is a 355 with aluminum heads and a roller cam.
