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'66 GT 350 flywheel- clutch question

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by Hockey44, Jun 13, 2009.

  1. Hockey44

    Hockey44 New Member

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    What are the most popular flywheel/ clutch combo's when mated with a T5? What are pro's and con's of different combinations? Is an alum. flywheel with steel insert something to be avoided? Looking for streetability and reliability as primary focus. Many thanks
     
  2. crzy4shelbys

    crzy4shelbys Well-Known Member

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    I installed a T-5 5 speed in my GT coupe (obviously not a Shelby, but all applies to a '66 Shelby). I bought a billet steel 157 tooth, 28 ounce imbalance flywheel drilled for a 10.5" clutch. The '66 clutch is 10", the 10.5" is the more modern clutch for the 5.0L Mustangs. I'm assuming your engine is either original or period correct (i.e. older than 1981 and hence uses 28 ounce imbalance rather than 50 ounce for the 1981 and newer 302's). The bellhousing style you use will also drive your clutch choice. Original style bellhousing has the release fork pivot on the drivers side (it's pushed by the linkage), but requires a spacer plate between the tranny and the bellhousing because it's input shaft is 3/4" longer. 5.0L style bellhousing pivots on the passenger side (it's pulled by a cable). The stroke of the throw out bearing is different depending on the pivot point, so if you're running a modern bellhousing/scatter shield, you probably want to run a 10.5" clutch. If you're running an old style bellhousing/scattershield, you probably want to stick with the 10" clutch. Of course if you're running a hydraulic throw out bearing in lieu of linkage, then scratch that. I didn't like the design of any of the kits designed to convert the regular pedal linkage to a cable setup, especially if you're talking about a real '66 GT350. Too much stress on the firewall. Some require welding to the clutch pedal.

    Personally, I'm running the following:

    157 tooth billet steel flywheel with 28 ounce imbalance, drilled for 10.5" clutch
    10.5" diaphragm style clutch (I like the centerforce, but some people state problems)
    T-5 style scattershield
    Hydraulic linkage (slave cylinder mounts to T-5 and pushes release fork from rear of car - effectively pulling it like the cable)

    I really like the hydraulic clutch linkage setup I have, but unfortunately the company that made it went out of business.

    Hope that helps,
    Josh
     
  3. 67200F5A02206

    67200F5A02206 Well-Known Member

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    In my 67 GT350 I'm doing much the same thing. Centerforce steel 157-tooth flywheel (28 oz) with the 10.4" (late model) clutch pattern. Centerforce dual friction clutch. Mcleod scatter shield. Original z-bar clutch linkage BUT the clutch pedal support has been rollerized and I have heim-jointed upper and lower clutch rods. Great pedal feel with no slop at all.

    Got the scattershield from Modern Driveline. Had to install the old style fulcrum so I could run my original clutch arm. Because the scattershield is the proper length there was no need for me to run a spacer plate - tranny bolts directly to the scattershield and the shifter is in the proper place.
     
  4. rsimkins

    rsimkins Well-Known Member

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    67200F5A02206,

    Could you post some info regarding the "rollerized" clutch pedal support and the heim-jointed clutch rods? I'd like to do the same thing. Thanks.
     
  5. 67GT500#2100

    67GT500#2100 Shelby Forums Pit Crew

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    I did the rollerized clutch pedal in my 66 fastback also. I used the Mustang Steve kit in the link below. However, I also used his cable linkage kit with a FRPP blowproof bellhousing and a T-5.


    http://www.mustangsteve.com/clutchbearings.html
    [​IMG]
     
  6. Cobrafixer

    Cobrafixer Active Member

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    My first car was a 70 Fastback with Boss 302 stripes (that was about 1984) the car has seen so many miles that the rod was eaten away, I had gone thorugh alot with that car, I used American Mustang in Ranch Cordova for the rollerized pedal support, I think its well worth the trouble of taking the dash apart, much smoother operation and I love the Centerforce Dual Friction clutches, it took a little while to get used to the light feel of the clutch after having a pretty heavy McLoead in there!
     
  7. Hockey44

    Hockey44 New Member

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    thanks guys for your thoughts. Yes this is an original GT350 except T5 swapped (got the original Borg Warner) to make it more streetable. Josh, you pointed out an interesting issue, namely the spacer required to keep the fork in the correct position. I am wondering what is the best way to be certain that the spacer is the correct height to ensure proper movement (and range thereof) of the fork? My local guy thinks that the problem I have had could come from namely the spacer being either to tall or short.

    He likes to use CenterForce although I gather the more folks you ask everyone has an opinion on diaphragm vs. fingers.

    Is "rollarizing" simply to make the pedal feel smoother or does this also effect clutch engagement/ dis-engagement? thanks

    Problem was that CF alu flywheel with steel insert warped (or too far out to resurface) and contact with plate only 30-50% so I believe an alignment issue. Now the fun- measuring weight on flywheel and transfering this to new flywheel.
     

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