Hello people bold text size?? Sorry..... I am running a mercruiser 470 and thought I would do it a favour and remove the exhaust riser to soak it in hydtochloric acid it cleaned up well. Now confusion time. The gasket set (2) has three holes to match the riser and manifold but the stainless plate blocks all 3 holes yes all 3... Is this a change/upgrade or a mistake? In short do I use the stainless plate which blocks of all 3 water journals/jackets.... My engine serial number is 5709796 for id as I am aware of different versions. Thankyou in advance for any help