So ……
how I approach installing any toyota rubber valve cover gasket is a mix of absolutes that were passed down by the guys with grey beards still wearing the Ivan Stuart rainbow

striped technicians uniform shirts back in the day ….
It’s been 2 decades or more since I installed a 3FE one so a bit of FSM refresh was in order …
Surface prep is 9/10 ,s of the law and that goes for the groove in the bottom of the cover , steel or aluminum…
The repeated wipe downs of the contact surface of the head to as bright as possible is key , and so is some strategic use of black FIPG oil pan and cam shaft housing sealer …
Take note the locking tabs details on the rubber oem gasket , I was shocked this puppy msrp usa was just shy of 40$ ..?
I always dry fit first , this ensures I have the correct gasket …
I apply a thin-moderate skim-kote to the entire rear , frint and all 4 radius turns too till then straighten out ..
Manually and carefully work the rubber gasket Around a bit at a time
In several passes ..
Once it’s it carefully flip cover and using a sanitary surface slam that puppy down hard , plumb , level and square …
I go at it like 3-4 times this seats all those important locking tabs and prevents it falling out or getting hung up
on one of the 4 male threaded studs , especially the last 1 in the rear …