[i4abuygto]

Helping a friend that has a new billet flywheel with the option to bolt up a 10.5 or 11 inch clutch kit on a 67 400 pushing approximately 425hp. Reading several related posts with no clear answers.
I have read that 10.5 inch has better grip but 11" will shift easier.
He is limited on budget - looking at the Luk brand.
Not looking for a lot of pedal pressure but want it to last - street driving with some burnouts expected.
Does the added weight of 11 inch make for slower acceleration of rpms?
Opinions and experiences are appreciated - thank you.

[74Grandville]

from what I understand larger rotating mass is not the right way to go about things. at your power level I would stay with the 10.5.

[72projectbird]

I've used 10.5" Centerforce Dual Friction clutches with great success. I haven't run any Luk brand clutches, so I cant comment on them. I also haven't run 11" setups.

I guess that doesn't help at all, now does it? lol

[Half-Inch Stud]

Power transfer across friction work better at the larger diameter. 11"
Borg-Warner pressure plate design for light pedal effort.

[i4abuygto]

Guys, Thanks for your thoughts. I know Pontiac went to the 11" disc on their 400 engines in the 1970s - there must have been a reason for the change.

[A.W.Dille]

I have an 11 inch bolted to the Hays flywheel in my 71 GTO. Was a rebuilt unit I got from AutoZone back around 2003 or 2004. Still in there, diaphragm unit. In my opinion, if you're going to use a 10.5 unit make sure it's a heavy duty unit and check to make sure that the damper springs in the disc do not rub the heads of the flywheel bolts. If they do then the clutch won't engage properly and will slip.

[64speed]

Also just FYI I have run all kinds of clutches and I have had good luck with ZOOM brand. Just as good as Ram or McLeod for usually half the price. The last one I used lasted behind a 66 389 with some serious abuse.

[i4abuygto]

Thanks guys,
It looks like that most are advising to go with the 11", which seems to make more sense, as Pontiac went to 11" clutches for the 400 in later years. I will look into the Zoom brand 11".
Any and all advice is welcome.
Thank you.

[The Champ]

Nothing wrong with the Luk brand you were looking at. When I put my 462 in my '64 GTO we put in a fresh clutch at the same time. I worked for an ACDelco warehouse distributor and so purchased an ACDelco unit at cost - it was actually manufactured by Luk .

Very happy with it.

[Tom Vaught]

LUK Clutches should have been installed in many Chevrolet Corvette vehicles over the years. You never hear of Corvettes with Blower Engines complaining about their 11" clutch systems.

Tom S likes the LUK Brand, (if I remember correctly some of his posts),
I like LUK stuff, The Champ runs the stuff, must be others out there who
have used their parts. Just saying.

We ran LUK parts in our 750 HP "Mule" 4.6L Vortech Engineering Vehicle.

We killed a bunch of Friction Discs and flywheels, when the "Test Drivers, NOT" would go 1st gear, 2nd gear,
then put the trans back into 1st gear when they were playing race car driver.
Many should never have been in the car but it was what it was.

Tom V.

[i4abuygto]

Thanks guys,
LUK 11" - I will check on a kit for a 67 Bonneville as all the 67 GTO kits are 10.5".

[i4abuygto]

Tis is what i found in a short searchhttps://www.ebay.com/itm/Luk-Clutch-Kit-New-Olds-Suburban-SaVana-Pontiac-Grand-Prix-Am-GMC-04-049/121957928214?fits=Year%3A1967%7CModel%3ABonneville &epid=76352796&hash=item1c65424d16:g:dXEAAOSwMBdb4 ~81:rk:4f:0#vi-ilComp

Any other links would be helpful

[i4abuygto]

Try this link - not sure why the other didnt work http://https://www.partsgeek.com/gbproducts/MC/16838-07083650.html?utm_content=MC&utm_term=1970%2C+1975 +Pontiac+Bonneville+Clutch+Kit+LUK+70%2C+75+Pontia c+Clutch+Kit&utm_source=google&utm_medium=ff&utm_c ampaign=PartsGeek+Google+Base&gclid=Cj0KCQiAjszhBR DgARIsAH8Kgvdk0YEh5EEVvnuahDSrNprOhrHnO6U5yVLCk6jD _Z73yCBDiOfvKoIaAl4uEALw_wcB&ad=47433950052

[danpaul]

I pitched my Centerforce duel friction for a Luk. Much better and was less than 1/2 the price.

[tom s]

I ONLY use McLeod B&B 10.5.I use diff lb ratings.My 421SD uses a 2800 lb,my 421HO uses a 2400 as does my 69 bird with a 450 HP 455.FWIW,old school.I surf the net(eBay) for NOS GM clutch disc.Tom

[Tom Vaught]

No wonder I can't find original GM 11" Clutch Discs, LUK does fine for my 64 GTO street car.

Tom V.

[i4abuygto]

I will advise on the 11" Luk setup - have to go Bonneville to get the 11"- I will show all and let the owner decide.

[track73]

I have had very good luck with the Centerforce 10.5 I got back in the mid 90's. It's in the engine on my signature along with an aluminum flywheel.