We can't answer you what and how much you should take, especially as you gave little detail on your previous experience, who you'll be with, etc.
Having said that, LSD tolerance should be almost back to baseline after 6 days. A very experienced friend of mine says LSD tolerance will last just 3 days though a more conservative number would be 3-7 days, the effect on the 6th and 7th day being negligible.