FP should be stock -- measure it/set it at 38/39 psig with the engine at a warm idle and the vacuum line pulled off the reg and plugged. Obviously, put the vacuum line back when you're done setting it. It will drop a few psig when you plug the line back in.
Plug gap - as much as you can and still get a reliable spark -- the stock .054" gap should be fine.
Timing - as much as you can get without getting detonation. I don't remember if you have iron or aluminum heads -- iron, I'd set it at 14 btdc and see what you get; aluminum start at 16, see if you can go 18. All set at warm idle with spout out -- of course plug it back in when you're done.
That's all for naturally aspirated -- if you're juicing -- that timing's got to be pulled back I expect. And if it's a dry set up -- see your instructions for how fp should be handled. Often, with nitrous colder plugs are recommended along with a smaller gap.
You can see it's not a one size fits all when you're running with and without nitrous.