11-inch clutch on a std 350 1972

[Dan D.]

[Patrick H.]

Re: 11-inch clutch on a std 350 1972

Dan, I suspect the books are wrong, as my mid June built 71 base motor 350 was the same way. 11 inch clutch when "the books" said 10.5 inches.

[Edward B.]

Re: 11-inch clutch on a std 350 1972

Dan, all Corvettes in 1972 had the 11" clutch except for the LT-1 (and ZR-1) with the M22.

Ed

[Tom P.]

Re: 11-inch clutch on a std 350 1972

I forget the year (69, 70????), Duke, John, or someone will know, BUT when the Corvette went to the 14in diameter, 168 teeth flywheel on ALLLLLLLL engines, then they ALL got the 11in clutch, of course, with the exception of those mentioned above.
The 55-62 engines also had the 14in, 168 teeth flywheel, but those earlier 168 teeth flywheels had the bolt pattern for the 10in clutch (now replaced with 10 1/2in clutches).
As far as I know, beginning with 66 models, the 168 teeth flywheels only had a bolt pattern for an 11in clutch, and only the smaller, 153 teeth flywheels had a bolt pattern for a 10 1/2in clutch. And this wasn't just with Corvettes. All across the board with Chevrolet products, if the engine came with a 168 teeth flywheel, it had a bolt pattern for an 11in clutch.
There were some service replacement 168 teeth flywheels with DUAL bolt patterns (10 1/2in and 11in), but I don't believe any production cars/trucks came with dual bolt pattern 168 teeth flywheels.

[Joe L.]

Re: 11-inch clutch on a std 350 1972

Dan------

11" clutches were used as follows:

ALL 1966-74 big blocks except L-88, ZL-1, LS-6 and 1969 with MA-6

ALL 1969-81 small blocks except 1970-72 ZR-1, 1978 with L-48, and, possibly, early 1979 with L-48.

So, your 1972 L-48 was definitely originally equipped with an 11" clutch. A GM #3899621 bellhousing also confirms that.

[Dan D.]

Re: 11-inch clutch on a std 350 1972

My thanks to Pat, Ed, Tom and Joe. I really appreciate your replies. It makes me happy I joined. I know that I've learned a lot just reading the posts, especially from the "frequent users". I've done quite a bit to this car over the years, but always with the goal of keeping it "original," which probably doesn't make a whole lot of sense since the car's nothing special. I just drive and enjoy it. Thanks again, Dan