The MERCRUISER housing I have is a 4 hose style as well. I know it's good. The reason I changed it out was it is a BRAVO style housing, and the engine went back into an ALPHA outdrive boat. It didn't restrict the water flow enough at slow speeds with the small outdrive water pump. I believe your VOLVO uses an engine driven raw water pump which is what this housing was for.
 
Here's a link to a picture of the style I have.
http://bpi.ebasicpower.com/mm5/graph...ER860256A4.jpg
		 
		
		
		
		
		
		
			
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				2011 SUNDANCE B20CCR SKIFF, 2011 YAMAHA 90HP 4 STROKE, 2011 KARAVAN SINGLE AXLE ALUMINUM TRAILER, LOWRANCE ELITE-7 HDI, MINN KOTA RIPTIDE TROLLING MOTOR
2000CC HYDRA-SPORT 225+HP EVINRUDE SOLD
AND THE PINK JEEP!!!! R.I.P.
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