MA6 option

[Rowdy Rat]

There were actually two different versions of the dual disk clutch that was used... A coarse spline (early) and fine spline (late).

The 1969 MA6 option for Corvettes was pretty much as you described... Available with L-71/L-89 only (not available with the L-88/ZL-1). GM records show 106 units produced for sale and I have around 15 or so cars surveyed with this clutch option. The 1969 cars used the coarse spline version which is probably the more difficult of the two to find today. Neat piece though... Great clamping force with very little pedal pressure required.

The LS-6 Corvettes used the fine spline version whether equipped with the M-21 or M-22 transmission. I have never heard of a 1970 LS-6 Chevelle equipped with this clutch, but I'm not well versed in Chevelles, so maybe someone more knowledgeable will speak up.

A few years ago, I was searching for big block parts and came across a complete L-72 engine for sale. Engine had an "LD" broadcast code (pretty sure that's the code - I did confirm it at the time though) and appropriate serial number derivative which corresponds to a "big" Chevrolet (Biscayne/Belair/Impala) with 427/425 and dual disk clutch... Yes, I did try to find the car (without any luck.)

That's the closest I ever found to a non-Corvette with a factory installed dual disk clutch.

Regards,

Stan Falenski

[442w30]

A similar, if not identical, clutch was available on the 1971 4-4-2 as well.

[LS6 RAT]

These clutches are very unique, the clutch assembly also uses a special thinner flywheel. For 1969 'vettes in conjunction with the 427cid, the units flywheel is internally balanced, for 1970 the special flywheel is externally balanced. Also interesting is the complete clutch assembly consisting of pressure plate, 10 inch disc, intermediary (floater plate)plate, 10 inch disc weighs the same as the standard 11 inch clutch assembly does.