Kyrasis6
+1y
It is the rear cam seal, can buy it at any auto parts store for about $4 The engine hook has nothing to do with holding it in, if it is not in correctly the hook will not save you. It is not likely you'll get it all the way in by just using you're hand.
The seal is actually held in by crush between the rear rocker arm cap and the cylinder head. The best way to put it in is to remove you're rocker arms install the seal then reinstall them.
Last time I did one I was able to get away with just removing the valve cover and loosening all the caps, then I pushed the seal part of the way in by hand. Once I had it partially started I placed a piece of flat steel over it and used a prybar against the firewall to push it the rest of the way in. Then I just retorqued all the rocker arm caps in sequence and reinstalled the cam cover. Took maybe 15-20 minutes. The seal is actually a metal cup which is coated with a hard rubber, it doesn't need any sealant but if you still want to use some any of the usual RTVs will work just fine.