There have been tests that show dinging header tubes has no effect on performance. (Roadkill Garage did a video on the subject that used to be on YouTube but Motortrend has since made it available only to paid subscribers.)

Rather than heating the idler arm and bending it, just take a BFH and a round piece of .120 wall tubing and create the clearance needed on the header tube. Piece of cake.

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64 Dodge Polara 426 Street Wedge - For when I want to go fast
99 Corvette Z-06 - For when I want to turn corners