The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Starting 1966 Factory Short Bed Build, Bagged, 383 Stroker and Muncie M20 4-Speed

88Stanger · 07-06-2020, 12:03 PM

Well that was an interesting conversation with a Fred at Mcleod Clutches. He explains to me that they have a .050 variance allowed in the fingers when installed. What they do is install each clutch onto a test machine and operate the fingers a few times as this will allow the stress in the fingers to equalize themselves and then as long as they are with-in a .050" of each other, they are good.
He also explained that on a hydraulic clutch system the throw out bearing is always touching the fingers and that the .100" to .150" is to allow the piston to move back as the disc wears and the fingers move.
His suggestion is to just mount it, take the middle of the fingers number and set the clearance to .150, that should keep me in between the .100 to .150 or there about. He stated that getting it dead on at .100 or even .150 is almost impossible and the the extra clearance rings they send are .150 thick anyways.
Very interesting conversation with him. Nice guy, makes some really good points on how these none race applications are. The fingers being heat treated will have some slight differences but all in all should be fine.
My issue now is i got a clutch for up to 400HP and i think the 383 will be over that a bit, so i am now sending this one back and getting the step up clutch, which by the way is only the disc, yes that is it, same clutch pressure plate but different disc, up to 550HP. Yes getting the disc would be typically be best, but that disc alone is $220.00 and the the complete kit is only $300.00, so i figure hell, just get a complete new kit and return the other one. Be interesting to do the finger height test before mounting on new kit and see how it measures out.

07-06-2020, 12:03 PM	#189
88Stanger Registered User Join Date: Mar 2015 Location: Washington State Posts: 1,644	Re: Starting 1966 Factory Short Bed Build, Bagged, 383 Stroker and Muncie M20 4-Speed Well that was an interesting conversation with a Fred at Mcleod Clutches. He explains to me that they have a .050 variance allowed in the fingers when installed. What they do is install each clutch onto a test machine and operate the fingers a few times as this will allow the stress in the fingers to equalize themselves and then as long as they are with-in a .050" of each other, they are good. He also explained that on a hydraulic clutch system the throw out bearing is always touching the fingers and that the .100" to .150" is to allow the piston to move back as the disc wears and the fingers move. His suggestion is to just mount it, take the middle of the fingers number and set the clearance to .150, that should keep me in between the .100 to .150 or there about. He stated that getting it dead on at .100 or even .150 is almost impossible and the the extra clearance rings they send are .150 thick anyways. Very interesting conversation with him. Nice guy, makes some really good points on how these none race applications are. The fingers being heat treated will have some slight differences but all in all should be fine. My issue now is i got a clutch for up to 400HP and i think the 383 will be over that a bit, so i am now sending this one back and getting the step up clutch, which by the way is only the disc, yes that is it, same clutch pressure plate but different disc, up to 550HP. Yes getting the disc would be typically be best, but that disc alone is $220.00 and the the complete kit is only $300.00, so i figure hell, just get a complete new kit and return the other one. Be interesting to do the finger height test before mounting on new kit and see how it measures out.