Clutch swap.

1st Official Post

    Hi, finding it hard to find a diaphram clutch kit for my 4/65 car. 3 finger style is to hard as i am getting older Have a new hi po z bar and bushings, now trying so source a kit that will match the flywheel bolt patern. Any one done this, and where did you source the kit, am in europe, so want to get it right when i order from U. S. Summit racing say i need to change the flywheel too Thanks.

    • Official Post

    I still use the Ford 3 finger type so I have not needed to source a diaphragm type for myself. It should help you to know that the 10" and 10 1/2" clutch fit the same flywheel. Therefore, being as you are seeking a 10 1/2" clutch, there will be no need for changing your flywheel for either size. The 10" size is for regular 289 engines in the Mustang and I am sure that there are many 10" versions out there. The flywheel change would only be needed for an 11" clutch which you do not need. That change would also involve the bell housing and starter which is even more reason to not look at an 11" clutch.

    I spent some time on the Summit site just now and they do not have a 10 1/2" clutch without a change to metric bolts and pins that are not on your Hipo flywheel. You may have better luck however I did find a McCleod 10" diaphragm kit which will fit your flywheel and be sufficient for street use. This kit is in their stock making it readily available. In the future you can easily replace just the disc when needed rather than the assembly.

    FORD McLeod Racing 75113 McLeod StreetPro Clutch Kits | Summit Racing

    I have used my 10 1/2" McCleod 3 finger clutch for over 45 years in my 427 Chevrolet which is now in my 66 Corvette.

    I did also find a Spec 10 1/2" kit at Summit but it is special order.

    FORD SPEC Clutch SF591 SPEC Stage 1 Clutch Kits | Summit Racing

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

    • Official Post
    Quote from Andy Spain

    The mcleod one shows a yes,i take it in the drop down menu its the stock option, and not 350gt.

    My intention was to lead you to a clutch that will work in your application which originally never used a diaphragm pressure plate. The original was a long style 3 finger without counterweights. Ford felt that the counterweights would be tougher to move at the higher RPM's encountered while flogging a Hipo 289. The counterweights force the pressure plate to grab harder at higher RPM's. The diaphragm is a good compromise for what you want. McCleod did not offer the diapragn clutch in the 10 1/2 size as a direct replacement for your original long style clutch. They only offered it in the 10" size which will be sufficient for normal street use.

    The SPEC clutch is offered in the correct 10 1/2" size but being a diaphragm is not a direct replacement for the original long style clutch. Therefore, neither of these clutches will show up on Summits drop down menu as a proper clutch by application. Computers are just not setup to show applications that will actually work as a replacement. Either one will do the job. You would need to move up to a racing version of the diaphragm clutch if you are planning to beat on your Kar. Keep in mind that the GT350 clutch is just a normal Hipo 289 clutch, although that is an improvement over the standard 289 clutch.

    Please keep in mind that I was a parts manager for Ford and Lincoln-Mercury dealers and I have been doing the Ford parts thing for over 50 years now. It is possible that you do not have an original pressure plate as the foot pressures on them are not extreme like some aftermarket replacements. If you send pictures of your pressure plate, I can see if that is an issue. If you want a genuine Ford Hipo pressure plate, here is one that is a tough find for only $999.00:

    1964-1970 Mustang GT Shelby Cougar NOS 289 HIPO BOSS 302 CLUTCH PRESSURE PLATE | eBay

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

    Hi Fred, hope the pic uploaded, clutch in now ram 92502 muscle car series from summit. So thats what i want to replace with a diaphragm style kit for light use, , 10 or 10.5 i don't mind,as long as the bolt pattern line's up Shipping and taxes alone about 160 dollars so i need to be right first time. Andy. The content cannot be displayed because you do not have authorisation to view this content.

    I was thinking maybe the 92502 ram muscle car series clutch i have in now, is a particularly stiff clutch anyway as its title suggests, any thoughts on that please Fred.

    I have been considering a clutch replacement myself. I put a high static pressure clutch in mine when I was young and dumb, almost 50 years ago.
    Reading up on that Ram says ‘ slightly higher effort than stock’ and is one of the replacements I considered. If that is true, and the it’s the clutch you have, might you have another concern creating your stiff pedal? It is difficult to find the published pressures, and is the stock pressure known?

    Ram does have a chart with 2 10.5 long style pressure plates. 1 is at 1800 lbs. part number 415, the other at 2600, part number 405. Is one of those in your kit number? Maybe their tech can tell you what you have as a starting point to have some idea.


    I think what we need to do is test some other cars at a show or two, if the owner will let us.

    Edited once, last by 289kford (May 26, 2024 at 10:35 PM).

    I emailed RAM, they told me that the pressure plate that comes in that kit is 2600 lbs. That is in the range the clutch I have in mine. It is too stiff for my liking.
    I don’t know what a stock clutch is, my guess is 1200- 1500..

    Interesting,and thank you so maybe just a regular 3 finger clutch, would require a lot less pressure. My concern with the diaphragm style wwhich for sure will be lighter is if the bolts don't line up, as its going to be costly and a pain to send back, but saying that Fred has suggested one, i would trust his judgement..

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