I used map gas with a pin point tip , I put vise grips on the retainer for a heat sink but I needed a lot of heat to get it apart , I have questions about the springs too , I still am sitting on the fence for a cam change so when I finaly come up with a cam I will change out all the springs too , I have a test & tune next weekend , I was hoping to test out rear end set up but now I am not sure if I want to run , its a murfs law thing , I put a lot of heat on it?