Vernalift 1500123
I used the Vernalift 1500123. 10"H by 10" Dia. Yes it is quieter. I got the side intake for ease of replacing the hump hose. I have a 1986 with the M25 and with the stock setup the mixer pipe and the inlet were almost touching. I bought a fiberglass 45 degree elbow with the muffler so it is much easier to work with. I have been talking to a mechanic and he was saying that the setup that I have proposed looks to be better than the stock setup as long as the waterlift muffler has the capacity to hold the extra water, and it should. Even though it appears to be smaller than the stock it will hold more water. By moving the exhaust hose out from under the sink it will free up some storage space. You would be amazed at how much room you will have in the engine compartment if you replace the stock aqualift.