Reddit mentions of Three Bond Engine Silcone Gasket 1211 - 3.5oz. TB1211

The passenger one is prone to leak more as it sits over the exhaust collector..
It's really not all that hard, the biggest issue is that unless you remove the timing covers, which means removing the timing belt. you have to tip the valve cover under the timing cover. Several tips:

1. Use Threebond 1211.
   
2. Be super meticulous cleaning up all the parts.
   
3. Let the sealant cure at least 24 hours.
   
4. Buy an offset ratcheting 10mm box wrench, you're welcome!
   
5. Remove all the parts to give you good access to the valve cover.
   
6. Once you have carefully placed the newly sealed valve cover on the head, stuff a towel or big rag in between the cover and the engine bay "wall", this will hold the cover in place well enough while you get the bolts in place.
   
7. Remember to use a clocking pattern tightening the bolts, like you do with lug nuts..
   
   Mine leaked, I put in new gaskets, it leaked, I resealed it, it leaked, I had the engine rebuild, it leaked, I used Threebond. It has been a couple years now, no leaks. I sear by the stuff now. People talk about the lack of space and it's not great like on an inline 4, but it's not the worst..
   
   Three bond:https://www.amazon.com/Three-Bond-Engine-Silcone-Gasket/dp/B000GZR4QC/ref=pd_lpo_sbs_263_t_0?_encoding=UTF8&psc=1&refRID=4MJJYYACMDPR6WCCRM06
   
   The type of wrench I mean: https://www.homedepot.com/p/GearWrench-10-mm-Reversible-Combination-Ratcheting-Wrench-9610N/202738029

Yea it should be good for a bit. I did a new oil cooler and seals because the old one had a crack in it and made an absolute mess of things. New pushrod tubes and seals, valve cover gaskets, main seal, transmission input shaft seal. Basically everything I could get to without pulling the motor apart too far. Also, this stuff is your friend