I've not had problems with engine bolts falling out, therefore I don't believe loctite is necessary, and is just asking for trouble and aggravation later.
For sure don't over tighten and deform sheet metal parts, then they do leak.

Follow Tim's advice.
Or I use gasket cement (contact adhesive) to similar effect on sheet metal covers/pans, one side only. Oil or grease on opposite side of valve cover so it's reusable. Permatex #2 on the other (or both sides) of gaskets I don't expect to save at disassembly.

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-