One thing is don't worry about the weight your adding there as Q200's need weight in the tail.  My Glass spring was stuck in about 1.5 foot.  It did break where it was stupidly fit into the steel tube going to the tail wheel assy.  I fixed that by doubling the diameter of the fiberglass rod and welding in a larger tube to the tail wheel.  Also the factory tail wheel pivots on an AN3 bolt.  I bent that bolt often.  Needs to be an AN4 at least.  Oh, and I had the lower rudder hinge break loose from the attachment to the plane.  Beef that up while your at it.

Fly Safe,