this is more as to the rite engs........old wing 61 new wing 72 flying sq old 975 new 1005. old weight 7.21 new weight 9.50, the kit is set for 60 size, have 2 great running 40 size st with macs pretune muffs 11x5 props at 12300 tip to tip on trops will be 3/4,,,,,,,,what do you guys think..............thanks