Speedracerntrixie is correct about the usual placement of landing gear for tail draggers. If anything, shedding the nosegear and adding a tailwheel makes an aircraft tail heavy. If you were happy with the way the airplane flew before the conversion than you should probably balance it at the same point on the wing as before. If the the "nose heaviness" is in regard to ground handling then the issue is gear placement. One other possibility is rolling drag in the main gear. Nose gear will tend to mask the problem if there is some drag in the main gear but it is like riding the brakes. If the airplane wants to tip onto its nose as it begins to roll that may be an issue. A bind in the wheels that doesn't seem like much at rest can have a greater impact as the aircraft speeds up. BTW that new canopy really makes the airplane.