1969 350ci/300hp C3 Clutch Diameter

[John S.]

What diameter clutch was OEM for a 1969 350ci/300hp Corvette? I'm replacing the clutch and want to order the clutch kit in advance of disassembly. I've received conflicting information regarding whether my car has 10.5 or 11 inch clutch.

The car is to remain as original as possible. The orig clutch lasted 88K miles and 41 years, so I don't see the need for an aftermarket clutch.

I plan to order the Sachs clutch kit through Zip.

Thanks for your help.

[Timothy B.]

Re: 1969 350ci/300hp C3 Clutch Diameter

John,

Why not keep the original and have it rebuilt.. You will need to do some research on where to send the clutch.

[Larry M.]

Re: 1969 350ci/300hp C3 Clutch Diameter

John:

Use Fort Wayne Clutch for rebuilding. www.fortwayneclutch.com Many satisified customers.

Another recommended NEW clutch is LUK RepSet. Often recommended for OEM-like performance. Google the name for a nearby dealer or you can order on-line. I THINK Paragon also sells this set.

Larry

EDIT: You should have an 11 inch clutch. If no one confirms, I will check the Chevrolet Parts Books for you later this morning to be certain. Currently going from memory.

[John S.]

Re: 1969 350ci/300hp C3 Clutch Diameter

Thanks for all of your help.

Larry-if you can confirm it is much appreciated.

[Duke W.]

Re: 1969 350ci/300hp C3 Clutch Diameter

I'm surprised Joe Lucia has not chimed in since he's owned a '69 350/300 since new. Maybe he's on the road. Send him an email, and he'll give you a complete rundown including OE numbers and current OE replacement numbers from Luk, Sachs, etc.

Or check the archives as he has provided this information multiple times.

Duke

[Wayne M.]

Re: 1969 350ci/300hp C3 Clutch Diameter

What diameter clutch was OEM for a 1969 350ci/300hp Corvette? I'm replacing the clutch and want to order the clutch kit in advance of disassembly. I've received conflicting information regarding whether my car has 10.5 or 11 inch clutch. ......

Per Jan '70 Corvette parts book:
#3908960, '69-70 Corvette (350) (exc. H/Per); woven (11").

[John S.]

Re: 1969 350ci/300hp C3 Clutch Diameter

The P&A catalog indicates the same pressure plate/cover part number for SBs from '63 to '69. The '70 part number changes for most 350s and indicates 11". One exception was the LT-1 engine that was part of the ZR-1 package. It has the L-88 flywheel and 10.4" clutch mated to the M-22 HD four-speed. "Civilian" LT-1s used the same 11" flywheel and clutch as base engines.

I'm surprised Joe Lucia has not chimed in since he's owned a '69 350/300 since new. Maybe he's on the road. Send him an email, and he'll give you a complete rundown including OE numbers and current OE replacement numbers from Luk, Sachs, etc.

Or check the archives as he has provided this information multiple times.

Duke

Thanks Duke, I had found Joe Lucia's info in one post but also a post from another person that said 10.5". Much appreciated.

I think I'm set for parts at this point. Hope to be driving the car in a couple of weeks and first judging experience in May.

I had found

[Duke W.]

Re: 1969 350ci/300hp C3 Clutch Diameter

Hold on! There is a page break in the listing, which confused me and the utilization doesn't make sense.

According to my '80 P&A catalog the 3884598 11" pressure plate/cover is applicable to '63-'64. I know that's not right!

There is also the 3841673, which apprears to be the 10.4" unit, but it doesn't reference the size

No wonder you are seeing conflicting information. The Corvette P&A catalog has errors, but my hunch is that yours is 11".

Duke

[Steven B.]

Re: 1969 350ci/300hp C3 Clutch Diameter

Yep, 11". If you do decide to rebuild your original Fort Wayne Clutch does an excellent job of refacing. Search them on the previous posts. We used to use FWC on an AP car. I used to live in Fort Wayne and toured their facility. They do first rate work.

Steve

[Duke W.]

Re: 1969 350ci/300hp C3 Clutch Diameter

GM used to sell the "plate" and "cover" (the diaphragm spring) separately or as an assembly. The last time I did mine I just bought a new plate, disk and bearing and surfaced the flywheel ever so slightly to eliminate the hard spots. The diaphragm spring was fine, so I reused it.

I don't think GM or the aftermaket sell the plate separately, nowadays.

Duke

[Timothy B.]

Re: 1969 350ci/300hp C3 Clutch Diameter

When I bought my 67 years ago the clutch had been replaced and I could not get the clutch to disengage completely even after adjusting all the free play out of the pedal.

Long story short, I removed the clutch and had Wareheim air brakes and controls send it for a rebuild because my friend who worked there said the pressure plate was not shimmed correctly. I can't remember where he sent it but no more problems.

Moral of the story.. get a quality job and rebalance the complete assembly, pressure plate, flywheel and make sure your pilot bushing is in good condition. Just use stock parts, you will have no more problems.

[Joe L.]

Re: 1969 350ci/300hp C3 Clutch Diameter

What diameter clutch was OEM for a 1969 350ci/300hp Corvette? I'm replacing the clutch and want to order the clutch kit in advance of disassembly. I've received conflicting information regarding whether my car has 10.5 or 11 inch clutch.

The car is to remain as original as possible. The orig clutch lasted 88K miles and 41 years, so I don't see the need for an aftermarket clutch.

I plan to order the Sachs clutch kit through Zip.

Thanks for your help.

John------

ALL 1969 Corvettes except L-88/ZL-1 and MA-6-equipped L-71 utilized an 11" clutch. I can absolutely guarantee you that 1969 300hp/350 used an 11" clutch. ALL 11" clutches were used in conjunction with a 14", 168 tooth ring gear flywheel.

The GM pressure plate and disc are long-since GM-discontinued. Last time I checked, the flywheel and release bearing were still available from GM, but they're not of the original part numbers.

[Larry M.]

Re: 1969 350ci/300hp C3 Clutch Diameter

John:

I was hoping Joe or others would comment to confirm the 11 inch diameter.

I did check the parts books I have, and they also indicated an 11 inch clutch......but as Duke and others have stated, there was some confusion/conflicting info in some of the books.

Hope you have all the info you need. Good luck.

Larry

[Joseph K.]

Re: 1969 350ci/300hp C3 Clutch Diameter

pargon has 10 3/8
corvette centeral 10 1/2 and 11 both with 10 tooth spline on both
Eclers 10.4 and 11 inch
midamerica has both 10.4 and 11 inch with 10 or 22 splines

I think you have to measure the unit you take off the car.

[Joe L.]

Re: 1969 350ci/300hp C3 Clutch Diameter

pargon has 10 3/8
corvette centeral 10 1/2 and 11 both with 10 tooth spline on both
Eclers 10.4 and 11 inch
midamerica has both 10.4 and 11 inch with 10 or 22 splines

I think you have to measure the unit you take off the car.

Joseph-----


As far as spline count, all 63-70 were 10 splines. No exceptions. 1971+ were 26 splines except 78-79 with L-48 and "Muncie" transmission.

As far as size goes, all 63-68 small block, 65 L-78, 67-69 L-88, 69 ZL-1, 70-72 ZR-1, and 78-79 L-48 with "Muncie" trans were 10-1/2 (10.4)". All others were 11".

I don't know why the parts books can't get this right. I suspect, though, that what they're doing is mixing things up with other Chevrolet applications. Some of those did differ from the above. For Corvette applications, the above is how it was.