Working Silent Choice exhaust system for Mercruiser 454. I think it works with a small block exhaust, too. Was on a 88 Galaxy 26' boat with a 330HP 454/Bravo 1.

Used, can text you a video I took of it working before I removed it.

Contains the 2 y-pipes, air actuators, air pump, outlets with rear flappers and switch. Hook up power and ground wires and it's working. I would replace the plastic tubing, and one connector screw is missing on one of the air actuators. Both are readily available. Asking $750

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