I did all my baffles with an air hammer and angled exhaust chisel. Other guys have done it with a piece of rebar with a cutting edge ground on the end. Be careful there is mesh all the way around the inside of the pipe with packing you don't want to catch that. I have done I think 12 sets now.

If you remove the baffles DO NOT remove the reducer cone at the header end or you will lose all your bottom end torque.

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