it's up to you (like duh)...a lot also depends on whether you have eaten recently too. i'm not much bigger so if i wanted a heavier trip i'd stick with the 3.5...

your best bet tho is ask a friend who's done this batch and see what s/he says. they can vary a lot depending on location and season of harvest, type, time gone by since harvest, etc etc etc.

happy trails to you!