Bolt size to cover up engine bay holes.

Being on Guam, everything rusts fairly quickly, when I had my lathe, whatever mild steel workpiece I was working on would flash rust in about an hour. I try to keep my tools and equipment out of the elements as best as possible.

 

That makes sense.

 

I would clean/grease them, but skip the bolts.

 

Why not use rubber body plugs like these with an anti-corrosive of some type? Some cosmoline or marine wheel bearing grease maybe? That would keep corrosion away and cover the holes without a bunch of random bolts everywhere. Although I will say it's nice to have spare bolts if you need to fix something and a bolt went missing.

$6 1/4" (0.25") Flush Mount Black Plastic Body and Sheet Metal Hole Plug - Qty 25

https://www.amazon.com/Flush-Mount-..._34?keywords=BODY+PLUG&qid=1583691909&sr=8-34

 

More likely to trap rust/moisture behind them.. and you wouldn't see the corrosion a bolt doesn't typically have much room to allow O2 into the threads to cause corrosion especially if the threads are coated with something like rtv, grease, or oil..

 

That stuff really works. I also use it on lots of things including my fishing reels.
I use it on my gas door hinge, hood latch mechanism...all the door hinges in my truck.
Stops corrosion on battery posts too!

 

I had my control arms installed by 4wheelparts and they removed this little power box of some sort and never screwed it back on anyone know the bolt thread and size? I believe it a 10mm

 

The 2 driver side are the m6 1.0 right?