You can use the stock hinge pins with the gt2 arms. You just have to cut them off with the dremel.
My main track had a double that I broke two arms on this summer. Never broke an arm before. I put the duece arms on and no trouble since.
I also broke two rear cvd's where they exploded at the coupler from shaft to axle. Rear one wheel landings seem to do it. lol Both times it landed cocked on one wheel then came down (no crash) and I nailed the throttle expecting to go and nothing. Kinda funny. I blame the power of the 6.5 and lipo, but I know it's the bad landings.
: )