[aussie merc]

I gather you have a 59A [center of head outlet] yes the original hoses had a lip moulded into them to keep the stats in place unfortunately replacement hoses dont have this so the fun begins. I personally went to stainless pipes and jam them down on the stats and clamp in place . Others use wire or modify the stats to keep them in place there are lots of posts on here about this so its up to you how you do this.