66-427 clutch fork ball stud

[Richard E.]

Can anyone suggest a Corvette Parts Supplier which sells OEM GM P/N 3887159,(1-3/8") clutch fork ball stud? GM dealer says the part has been replaced by one with different dimensions. I prefer to use the correct part. Thanks all for considering my requist.

Rich

[Joe L.]

Re: 66-427 clutch fork ball stud

Rich-----

As far as I know, the GM #3887159 is not reproduced or otherwise available in the replacement parts market. GM replaced it years ago with the GM #3729000 which is 1-1/2" long. I think that you will find that the 1-1/2" stud will work as well.

One POSSIBLE source for a 1-3/8" stud might be Dorman/Motormite. I don't think that they offer this stud, but if anyone does, it would be them.

There are likely plenty of these things around USED. Just find a 1966-75 bellhousing and it will likely have one in it. However, in my opinion, USED studs are not desirable; this is a part that you want to replace with NEW. In fact, you probably already have a USED one.

[Joe L.]

Addendum

One other thing that I should have mentioned, you can obtain ADJUSTABLE ball studs from high performance sources like Summit, etc. With one of these, you could adjust it to 1-3/8" length. Of course, it won't be otherwise configured like an original stud, but it should perform just like the 1-3/8" original. Personally, I would not use one of these, but it is an option for you.

[Richard E.]

Re: Addendum

Thank you Joe. Is this the Dorman that sells fasteners of all types that you are referring to?

[Michael M.]

Re: Addendum

Joe, I believe you are right that an adjustable ball stud is not desirable, but if it is necessary, the best thing to do is adjust it to the desired length and then tack weld the adjusting nut in place. This way there is no danger of it coming loose and out of adjustment. People have been using these studs with success for many years.

[Joe L.]

Re: Addendum

Rich-----

Yes, it is. However, I have since checked the Dorman offerings. They only show the 1-1/2" stud. So, if the 1-3/8" stud is out there somewhere in "auto replacement parts land", it would be of some other brand.

[Richard E.]

Re: Addendum

Joe; Very much appreciate your research on this. I will use the 1 1/2" GM replacement. I think it will work, there should be sufficient adjustment in the linkage to compensate for pedal travel / freeplay etc. Maybe someone reading this has used the replacement and will comment on adjusting. Thanks again.

[Joe L.]

Re: Addendum

Rich-----

I've used it without problems on my 1969. While there are some differences between a 1966 and 1969 clutch actuating system, I don't think that there will be much difference as far as the effects of the replacement ball stud go.

Prior to 1966, the 1-1/2" ball stud was used in PRODUCTION for all Corvettes. After early 1975, GM went back to the 1-1/2" ball stud in PRODUCTION for all Corvettes through the 1981 model year. The 1968-E1975 clutch actuating system, which originally used the 1-3/8" ball stud, was EXACTLY the same otherwise as the L75-81. Yet, GM reverted to the 1-1/2" stud for the latter.

Yes, it is true that 1966 did use some clutch actuating system components that were different than 1967 and later. These included the clutch fork push rod, original fork (for your application) and cross shaft assembly. 1967 is exactly the same as 1968 and later except for the pedal pushrod (different only because the 67 cockpit/firewall configuration is obviously different than later). However, I do not think that the 1-1/2" ball stud will cause you any problems. GM doesn't think so, either; they catalog the 1-1/2" ball stud as the approved replacement for your application.

Notwithstanding any of the above, if I were dealing with a 1966 Corvette and I had a 1-3/8" ball stud that was serviceable or if I could obtain a used replacement in EXCELLENT condition, I think that I'd use it. It would be a somewhat "anal" thing to do, but I think that I'd do it.