I have my eye on a trek 660 circa 1985. I will need to cold set the dropouts.
Sheldon seems to be a fan of the 2x4, and another site advocates using all thread, nuts and washers with a crescent wrench and an alternative to this is to use a turn buckle to make sure that one turn is one turn.

Then there is something about using string to align the frame?

Can anyone shed some light on this mysterious process for me.

Thanks