I changed a few things with mine. One was the fuel tank, and that was after having the stock one split. I should have listened from the start... I placed my battery as far back in the tail as I could, because I wanted an aft CG. One thing quiet a few people mentioned was reinforcing the landing gear block, but I didn't find it necessary. Mine just kisses the ground when it lands, and I really do want to keep it as light as possible. Before this next season I'll be replacing the metal motor mount with something lighter, both to move the CG further back and lower the weight just a bit more.