Close fits will give maximum strength. I prefer a close push fit for accuracy. As you can see there's barely any difference from zero to three thou (this is from Henkel's literature).

Loctite 601 is a good choice as it's high-strength, low viscosity (good for small gaps) and its fixture time is long at 25 minutes.
Loctite 603 is another good option as it's tolerant of light oil/grease contamination (think dirty fingers not dipping in neatcut) but is thicker than 601 and fills gaps up to 5 thou, (~0.13mm), fixture time of 10 minutes (full cure time is 24 hours) and high shear strength.
Oddly my 2017 technical guide to Henkel products (which runs to about 300 pages) doesn't cover 601, but it's certainly still available.
Neil