Option MA-6
I am trying to locate the GM part number associated with the MA-6 option and also the individual part numbers for both the pressure plate and the cluthes. I was cleaning out some boxes from years ago and found this dual cluth assembly but the original box has about turned to powder. The only good numbers are on the cluth plates and they both are "GM9049 PB" then "US-969X" and the "Veelok". The pressure plate only has "Borg & Beck" is does have the purple dye on it and the unit if for a 10 spline. Can anyone confirm if this an MA-6 option and if so what would the part number be and is it Group .088. Thanks In Advance For Your Assistance.
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Re: Option MA-6
Ron-----
It sounds like an MA-6 unit from what you describe. MA-6 discs did have "Veelok" stamped on them. However, I expect that many other clutches did, too.
Original PART numbers for the 1969 MA-6 were as follows:
flywheel-----GM #3955151
friction disc (2 required)----GM #3959176 (10 spline)
pressure plate assembly-----GM #3959175. This assembly includes the cover, dual pressure plate assembly, and ONE of the GM #3959176 friction discs.
The 1971 dual disc clutch used with all 4 speed equipped LS-6 used the following:
flywheel-----GM #3992094
friction discs (2 required)----GM #3993815 (26 spline)
pressure plate assembly------GM #3993814. This assembly includes cover, dual pressure plates, and ONE GM #3993815 friction disc.
The 3959175 and 3993814 were discontinued in July, 1972 and replaced by GM #231254. The latter assembly included NO friction discs and they both had to be obtained separately.
The GM #3955151 flywheel was discontinued in April, 1981 and the 3992094 flywheel was discontinued in July, 1983.
The GM #3959176 friction disc was discontinued in June, 1982 and the GM #3993815 friction disc was discontinued in October, 1985.
Finally, the GM #231254 pressure plate assembly was discontinued in November, 1988.In Appreciation of John Hinckley -
Re: Option MA-6
Ron,
Those MA-6 HD clutch assemblies are very difficult to get. I've had several, they are practically indestructable. Gib Hufstater, Zora's right hand man invented this unit.
Originally conceived to alleviate leg fatigue from the grueling hours of the SCCA Trans Am racing and countless shifts during the race. These clutches were way ahead of their time.Comment
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Re: Option MA-6
Joe and Warren thanks for the replys. I was not sure but you have now confirmed my thoughts. I was hard because there is no part number on the pressure plate and as you suggested Joe, others clutches had "Veelok". I appreciate the assistance. Many Thanks, Ron
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Re: Option MA-6 (eary 1969 unavailability)
Just a bit of trivia. From August 1968 Chev Denver Zone Newsletter (Vette Vues, Dec '92).
"Current indications are that RPO MA6 Heavy Duty Dual Plate Clutch will not be available for production at the assembly plants until mid-October. Orders should not specify RPO MA6 on units which earlier production would be anticipated"
My question: Was MA6 (or its equivalent) embedded with any of the other low-production high-horse engine combinations through 1972 MY ?Comment
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Re: Option MA-6 (eary 1969 unavailability)
To my knowledge, MA6 could not be ordered as a separate option, but was only included with specific engines. I believe the MA6 clutch was first used in 69 as an included option with 427 engines suffixes LT, and LU...I think the LT suffix is the L71, and maybe LU is the L89.
Antonick's Black Book only mentions MA6 as "HDC", or Heavy Duty Clutch...it is not listed in the list of regular options. He also mentions this clutch only for 69 MY applications above as for as I know. The 71 LS6 application is one I didn't know about, and Antonick doesn't show any special clutch notation for 71.
In 1990, I looked at an original owner 69 L71 for possible purchase that had the MA6 clutch...this was before I knew anything about Corvettes except not having the original engine was BAD!; I wish I could have that chance back...it had a CE block installed during it's first year.Last edited by Chuck S.; May 6, 2008, 08:46 PM.Comment
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Re: Option MA-6 (eary 1969 unavailability)
Wayne-----
Other than 1971 LS-6 for which the dual disc was standard (obviously, only for those with 4 speed transmission), the dual disc was ONLY used for 1969 with L-71 and the MA-6 option. Some folks mistakenly think it was used for L-88. It was never available in PRODUCTION with an L-88, though, either as standard equipment or as an option. L-88's used a lightweight, 12-3/4" flywheel. The MA-6 set-up used a decidedly non-lightweight, 14" flywheel.
The MA-6 clutch was not used in PRODUCTION for any other Chevrolet besides Corvette. Of course, it MAY have been used for some COPO-origin cars, but none that I'm aware of.In Appreciation of John HinckleyComment
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Re: Option MA-6 (eary 1969 unavailability)
Chuck-----
MA-6 was an RPO but only for 1969 and only with L-71. When one ordered that option, one also received an engine with a specific suffix code since that's how the option was effected---clutches were part of the engine assembly as supplied from Tonawanda.
All 1971 Corvette with LS-6 and 4 speed were equipped with the clutch formerly known as option MA-6. Actually, it wasn't exactly the same set-up because the flywheel was counterweighted (as required for all 454 cid) and the friction discs were 26 spline (as was used for all 1971 and most, but not all, 1972-81).In Appreciation of John HinckleyComment
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Re: Option MA-6
Joe,
I am hoping you can clear up one other aspect for me. I thought I remembered read that the 2 ZL1's used the 10 spline MA6 and that it was also adopted for the ZL1 Camero's. I was wondering if you could clear this up for me. Thanks, RonComment
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Re: Option MA-6
Ron-----
I am totally unaware of either of the applications you mentioned for MA-6 clutch. I don't think that an MA-6 clutch was ever used for ZL-1 and GM also indicates it wasn't.
As far as the Camaros go, they were COPO so, I suppose, just about anything is possible. However, to my knowledge, they used the same 12-3/4" flywheel and 10-1/2" clutch as Corvette ZL-1's.In Appreciation of John HinckleyComment
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Re: Option MA-6
Thanks everyone for the information it has most helpful and as always educational!!Comment
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Re: Option MA-6
...just to split hairs further; the MA6 was used not only on '69 L71's but also on '69 L89's. I know of at least 3 Corvettes with this combination.Comment
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Re: Option MA-6
Although MA6 was listed in one version of the 1969 Camaro Dealer Ordering Information, none were ever built; it was only an over-the-counter "off-road" part for Camaros (listed with a GM part number so it was legal for SCCA/Trans-Am usage, like the cross-ram intake kit and "-140" cam).Comment
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