MFER-1 mod is plenty loud. No need for exhaust upgrade. Maybe some ear plugs though lol

[Jungle Cat]

Appreciate the work you military and aircraft mechanics do. Father was a jet fighter mechanic fior 20 years too. Had terrible hearing too, Most of the years he was in they had ridiculous orange hard rubber earplugs with long stems. He said they worked like shit. Late in his career they used the head phone types. Too late at that point.