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B. W. · 03-04-2017, 03:50 PM

the stock pulley has a larger center bore & bolt pattern because the fan clutch screws onto the water pump hub rather than using the four bolts to hold it on

03-04-2017, 03:50 PM	#2
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Water pump for L31 with Serp the stock pulley has a larger center bore & bolt pattern because the fan clutch screws onto the water pump hub rather than using the four bolts to hold it on Attached Images Last edited by B. W.; 03-05-2017 at 11:35 AM.