Now, mark that location with a piece of tape. Carry both the seatpost clamp wrench and seatpin wrench. Note how you feel riding, Try moving the position a little closer to what you had, Better? Do a little more. Worse? Try sliding the seat further still, keeping a record of where you started and the past position, Go (in the direction of the change that makes things better) until your body says "too much" and back off to the last setting.
Moving the seat back means it is probably higher than you started and perhaps should come down. Same rules apply to seat height. You may also find that the best tip for your seat has changed.
3'4" is a huge change. Almost like going out and buying a new bike. (I too consider 1/8" quite real.) But it sounds like you are on to a discovery of what works for you. Keep experimenting. (One equipment change that will make the experimenting much easier is a two-bolt seatpost. Thompson and some of the Nittos come to mind and there are others. Advantage is that you can loosen just one bolt, slide the seat and retighten without changing the tilt or loosen the one, make a small adjustment of the other, re-tighten the first and make incremental tilt changes.
Ben