Hello,
I bought this kit brand new in around 1985, Wing Ding 60. Built it at that time with advice from a experienced rc boat racer in Sacramento. There is a 2° wedge between the strut and transom. 3/16" flex shaft, strut, rudder assembly from Octura. Turn fin moved out to the sponson and a K&B 67. I ran it about 4 times through the yrs. But when it goes through the turns, the tail likes to bounce up and down a little. I still have the boat. If your interested, I can show you a paper with the sponson, strut, total weight and cg.
Arne.