sam,with used engines......the first thing i would do would be take it apart and have a look at it inside......or have a local nitro racer or friend help you do it.....you might find something that could be addressed that might save you frustration with used engines.....ie bearing,rod slop,crank issues,sleeve etc......hows the pinch?
If you dont have any concerns in that way,because you bought it from your best friend and know how he treated it then........
Even with a New motor,i have a habbit of counting where they have their settings at.....and recording them... and my adjustments as time goes on........screw them in in half turn increments and see where they are set..... take notes...put them back where they where........most engines will run with the HSN set flush with the barrell....Fat but run.....you should be good to go sounds like you have a grasp on tuning a bit....
now if it where me,I would crank it up and see how it runs were it is set....after i looked at it.....unless the HSN is in the bottom of the barrell!...LOL!