Re: engine gaskets and head bolt ?
Chase those threads and wire brush the bolts. The taps are cheap and wire brush cheaper. You can get a false torque reading if the threads aren't clean. Ditto on the loctite. I will add that I like to retorque my head bolts if it's my engine so I don't use loctite. The reasoning for both methods is the engine and bolts all heat up, expand, then contract at different rates and the bolts will loosen up ever so lightly... or maybe a little more after awhile. Since I have easy access to my engine in my boat it's no big deal. Any engine I build for someone else will be loctited and each and every head bolt on my own or someone else's engine marked with a marking paint pen so I don't miss any and so I know exactly where I am in the tightening sequence after I go grab my 4th beer.
Oh and keep a vacuum handy to clean out the junk from the threads I use duct tape and a small copper tube attached to the vacuum hose so I can get down in the holes. You can also vacuum out the cylinders just before assembly. Just tell wifey you're vacuuming out the head..... bolt holes. Keep the cylinders clean cover them if you can. Tiny particles down between the piston and the cylinder wall resting on the ring will scratch the walls.
