hello, i have a matrix fre that i bought used so i do not have the manual,and it did not come with the preloads.i try to use my nephews preloads from his kyosho but where to small,where can i buy just the preloads.iam thinking of replacing the shocks with some threaded ones. what are the sizes of the matrix shocks. i want to make sure i buy something thats going to fit. or if you know of certain brands that fit let me know. thank you.