McLeod Clutch Differences
Thread Starter
Old Fart Pilot
Joined: Apr 2010
Posts: 1,932
Likes: 1,001
From: Spokane, WA
McLeod Clutch Differences
I'm shopping for a new clutch to use when I reassemble my '71 coupe. The original 350/270 engine has been rebuilt with a mildly upgraded intake and roller cam & rockers, but I stayed with the original 487 heads. Tranny is the original M20 4-speed. Car will be a weekend joy rider, not a racer. After reading the thread about clutch disengagement clearance distances, I'm interested in using McLeod clutches. But first I want to to get some input from the forum on the difference between the 11" Street Level ones and the Street Pro ones. I know the SLs are good for up to 300HP/300TQ and my engine might be getting close to that, especially if I upgrade the exhaust for better flow. That then moves me towards the SPs which can handle 400HP/400TQ.
Both are single organic discs, so what allows the SP to handle more power?
Is it simply a difference in the pressure plate clamping force or something in the disc springs or disc composition itself?
Will the SP require more pedal force to disengage the clutch? [just in case my wife "steals"
(borrows without my knowledge) the car for a joy ride ]
Any difference in longevity between the two?
Thanks for your help,
Paul
Both are single organic discs, so what allows the SP to handle more power?
Is it simply a difference in the pressure plate clamping force or something in the disc springs or disc composition itself?
Will the SP require more pedal force to disengage the clutch? [just in case my wife "steals"
(borrows without my knowledge) the car for a joy ride ]Any difference in longevity between the two?
Thanks for your help,
Paul
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
The Street level has a fiber friction plate on both sides......the Street Pro has ceramic on one side (I believe the flywheel side).
I have the Street Pro and it is as good as it gets for pedal and grab......not heavy at all.
Jebby
I have the Street Pro and it is as good as it gets for pedal and grab......not heavy at all.
Jebby
Drifting
Joined: Dec 2011
Posts: 1,743
Likes: 289
From: Chardon Ohio
I had both the McLeod 75121 Street Pro and it was fine, I upgraded my motor to a 383 stroker and got the 75221 Super street pro and it's great. 75121 is rated for 400 HP, and the 75221 is rated for 500 HP. The 75221 is not a heavy clutch and has worked perfectly for me. 
Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
the “super” street pro is the model with a ceramic side that faces the flywheel.
the street pro is organic on both sides.
I’ve had both of these clutches and both perform well. My experience after going to replace the super street was that the ceramic side chewed into my flywheel pretty good. In my opinion the ram power grip is a better set up with the ceramic facing the pressure plate.
anyway that’s a bit off topic. I don’t know what makes the power threshold lower on the street level vs the street pro, but I’d put the street pro behind most non-crazy motors without a worry. It’s a perfect upgrade for stock replacement, and a bit further up the food chain too.
Last edited by Big Block Dave; Feb 2, 2021 at 09:07 AM.
Le Mans Master
Joined: Jun 2019
Posts: 7,670
Likes: 2,475
From: Indiana
i got the street pro.
VERy happy.. clutch equal to or better than what was in it. note i bought another bushing as it was magnetic in the kit.. i paid 199..
here is my clutch
79 l82 m21 manual super t-10 transmission removal, rebuild, clutch, shifter, etc diy - Page 2 - CorvetteForum - Chevrolet Corvette Forum Discussion
here it is in action
my first you tube video breaking in my DIY rebuilt transmission and McLoed clutch - CorvetteForum - Chevrolet Corvette Forum Discussion
VERy happy.. clutch equal to or better than what was in it. note i bought another bushing as it was magnetic in the kit.. i paid 199..
here is my clutch
79 l82 m21 manual super t-10 transmission removal, rebuild, clutch, shifter, etc diy - Page 2 - CorvetteForum - Chevrolet Corvette Forum Discussion
here it is in action
my first you tube video breaking in my DIY rebuilt transmission and McLoed clutch - CorvetteForum - Chevrolet Corvette Forum Discussion
Last edited by interpon; Feb 2, 2021 at 09:29 AM.
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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I talked with McLeod looking for part numbers from the pressure plates....they are all the same, all the torque and Hp differences are in the discs materials themselves. I smoke a street level clutch before. The super street pro is very nice.
McLeod has a break in period with their clutches as well which makes a difference on their life and quality of drive
McLeod has a break in period with their clutches as well which makes a difference on their life and quality of drive
Last edited by Rescue Rogers; Feb 2, 2021 at 01:00 PM.
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Le Mans Master
Joined: Nov 2003
Posts: 5,772
Likes: 694
From: Maryland
St. Jude Donor '05, '09, '15
The McLeod Street Pro 75121 has a 26 spline disc. I think your Muncie has a 10 spline main shaft. Not compatible unless they are swapping the disc for you.
I think you want a 75124.
https://www.summitracing.com/parts/m...-size/5-7l-350
Tom
I think you want a 75124.
https://www.summitracing.com/parts/m...-size/5-7l-350
Tom
Last edited by Sky65; Feb 2, 2021 at 08:05 PM.
Thread Starter
Old Fart Pilot
Joined: Apr 2010
Posts: 1,932
Likes: 1,001
From: Spokane, WA
The McLeod Street Pro 75121 has a 26 spline disc. I think your Muncie has a 10 spline main shaft. Not compatible unless they are swapping the disc for you.
I think you want a 75124.
https://www.summitracing.com/parts/m...-size/5-7l-350
Tom
I think you want a 75124.
https://www.summitracing.com/parts/m...-size/5-7l-350
Tom
Much to my relief, I quit counting after 16 splines so I believe I'm good to go!!
Paul
Le Mans Master
Joined: Nov 2003
Posts: 5,772
Likes: 694
From: Maryland
St. Jude Donor '05, '09, '15
Summit and McLeod both said the 75121 was correct for my year Corvette. You got me worried that my memory of many more than 10 splines was screwed up, so I just had to double check...
Much to my relief, I quit counting after 16 splines so I believe I'm good to go!!
Paul
Much to my relief, I quit counting after 16 splines so I believe I'm good to go!!
Paul
Sorry if I confused things.
Tom
Le Mans Master
Joined: Jun 2019
Posts: 7,670
Likes: 2,475
From: Indiana
buy the bushing in slide #9.. it was non magnetic vs what comes with it and local and cheap and USA
Clutch recommendations please 79 l82 - CorvetteForum - Chevrolet Corvette Forum Discussion
Clutch recommendations please 79 l82 - CorvetteForum - Chevrolet Corvette Forum Discussion
Race Director
Joined: Sep 1999
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From: Plano TX