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| | | | Joined: Feb 2016 Posts: 114 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 114 | I want to get a new clutch for the rebuilt engine I am installing, but I have run into a conundrum. The kits available are for 10.5" and 11", but mine measures at 11.75". Is this a correct reading? 11" is a "reference" size? The engine is a 350 SBC, mating to a muncie sm420 with a Ranger overdrive installed. | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Casey_58, I am going to assume that the 11.75" clutch is the one that fits your flywheel for the new 350. That clutch would probably be referred to as a 12" clutch, usually only found on heavier trucks. If I am remembering correctly a 12" clutch is the largest clutch that will fit in the stock bellhousing, hope that helps. | | | | | Joined: Feb 2016 Posts: 114 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 114 | Any ideas on where to find one? All I am getting is either 11" or something other than 10-spline. | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Casey_58, these part numbers are from Napa and the prices are "reserve online price"
Their p/n NCF 1104064 which is a diaphragm type 11.75" ten spline 1 1/8" input $123.99
NCF 1104902 which is a coil spring type 11.875" ten spline 1 1/8" input $158.99
hope that helps. | | | | | Joined: Feb 2016 Posts: 114 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 114 | Huh, I can't tell which is better, coil or diaphragm. What is your suggestion? | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Casey_58, the diaphragm clutch is easier on your leg, when being built coil spring clutches can be tailored as to their clamping force by which type of springs are used in the assembly, the stronger the clamping force the more effort is required to depress the clutch pedal. Most of the coil spring clutches I have seen in my career have had a mixture of different strength springs in them. Seeing as how we have no idea what strength of springs are in Napa's coil spring clutch maybe the diaphragm clutch would be the better choice for you, hope that helps. | | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | My two cents would be, if you are using your truck to haul heavy loads, get the coil spring type, if you are not hauling anything heavy and just driving it around town get the diaphram type. Mike B  | | | | | Joined: Feb 2016 Posts: 114 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 114 | I will call Napa tomorrow, maybe they can tell me more about the clutches. | | | | | Joined: Feb 2016 Posts: 114 'Bolter | | 'Bolter Joined: Feb 2016 Posts: 114 | Looks like I'll stick with the coil spring clutch, thanks for the input, everyone. | | |
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