I feel there is one that will work better. The stock one has to comprimise to meet certain standards and such. Works good stock but not for maximun ouput. My only issue is that cams will lower dynamiccompression so with my 1.9 head it"ll get a little more finicky depending on the cam. May try to put 1.6 precups in my 1.9 head. Than i can afford to mill the valve reliefs. I'd be happy with 20:1 or so. I also think a custom or gasser long runner would help no to low boost opereation when combined with a cam.