Liners are hit and miss. Standard or Modified they can fail. With or Without a block mod they can fail. I was running 300+ bhp without the Block Mod and mine was fine. It is literally a lottery whether or not they fail. As for Shafts it all depends on your driving style and how hard you want to launch the car. Again mine was tracked and driven hard but never "launched" and never had an issue with them. I loved the ST and would have another in a heartbeat if I had the room