GW 30cc Acro into P15 pattern model

The vertical tail of Gold Wing 30 cc V3 series was operated in two pieces following my ordinary manner in order to eliminate the poisoning discrepancy, twisted fuselage in addition to distorted vertical stabilizer to the right side. The adjusting reference is the main wing connecting carbon rod. For extending the tail moment, the horizontal stabilizer would be set at 75 mm posterior position, this is an indispensable arrangement to modify the innate acrobatic model into my specific purpose, P15 maneuver stunt performance, because too short tail moment arm causes some unstability that is inconvenient for drawing F3A patterns in the sky. Basic construction of GW 30 cc acro model is almost the same as popular recent P15 stunt models, except the finished weight. I wonder if I could carry out to do that within 5 kgr? The limited weight must be cleared at any rate, otherwise, it would be far impossible to be an applicant of F3A competitions in future.