Most of us use RTV ot "The right stuff" sealant for the ends.
For either stay towards the inside of the rails where the cork used to go and put about a 3/8 bead all along it and into the corners where the heads and block meet.
Set the intake on as fast as you can and get bolts in it and allow the sealant to set up for at least a few hours.
It helps to have two people to set it on so you don't end up sliding it around at all when it goes down.
Make sure the original locating dowels are removed from the block first.