Sorry mate, but have you had any training? I'm not a pro team mechanic but I've been trained to work on suspension, made a living doing it and been told to use propane torch.

It takes 1200F+ to melt aluminium, no chance you can get it that hot in 10-15 seconds. Just to help you visualize aliminium vs flame, think of the internals of you NSR engine where aluminium piston and aluminum cylinder are exposed to combustion temps well above the propane torch output.

I do want to warn you about using open flame near any flammable stuff like gas (pertol or whatever you call it)