I didn't use the plastic holders on mine i just put a thin layer of rtv on the gasket and set it in place then did the same on the other side then set my intake on. So far no leaks. With the valley part I used the gaskets and used a pretty thick layer of rtv on both sides. I know alot of people just do a single bead of rtv with no gasket but mine had a pretty large gap im assuming its probably where I milled my heads and didn't mill the intake to match. But I used the cork gasket in the kit with a liberal amount of rtv no leaks there either. The last photo is the gap between the block and intake.