1967 big block half shaft part numbers

[Jill G.]

I am restoring my 1967 big block corvette. The half shafts have these part numbers stamped on the inside at each end: left side half shaft shows GM 122A and 3707775 underneath that GM no. and on the opposite end there is GM 122B and 3707775 stamped underneath it. The right side half shaft shows GM 79A on one end and GM 79B on the other end with the 370775 number stamped underneath.
Are these correct half shafts for my car? If not, what do they belong to? According to Joe Lucia e-mail on Jan. 17, 2002 the number for the 1967 big block is #3872908. Thanks in advance for any information on these numbers.

[Joe L.]

Re: 1967 big block half shaft part numbers

Paul------

The number that I provided earlier which you referred to is the PART number for the complete halfshaft assembly. This number appears nowhere on a half-shaft EXCEPT for SERVICE half-shafts which have the number stencilled on them. The numbers that you provided are forging numbers for the half shaft yoke ends. The 3777075 number is among those used for 63-74 half-shafts and was used on 67 big blocks. However, these numbers are the same as those used on small block half-shafts, as well. The only difference between 65-74 half shafts is the fact that the big block half shafts were shotpeened and the small block were not.

[Rob A.]

Re: 1967 big block half shaft part numbers

The halfshafts on my '67 big block are numbered EXACTLY as yours. I have every reason to believe they are original to the car.

[Jill G.]

Re: 1967 big block half shaft part numbers

Thanks for the information and clarification Joe and Rob. I failed to mention it but, I believe my half shafts to be original to the car as well.

[David Dawdy]

67 BB half Shafts

How do you identify the BB half shafts? Is the metal surface different?

[Joe L.]

Re: 67 BB half Shafts

David-----

Yes, the big block shafts are shot-peened and, consequently, have a VERY slightly textured and "dull" surface as compared to the smoother surface of small block shafts. Otherwise, they are exactly the same. In a used shaft which has rusted or a used shaft that has been bead blasted to clean up the rust, there is NO WAY to tell the difference. The difference would only be apparent when the car was new or on an NOS shaft.

[John H.]

Re: 67 BB half Shafts

That's why the BB half-shafts originally had a dab of green paint on them in production so the operators could visually identify them at the manufacturing source and get them in the right shipping containers, and so the assembly guys could identify them and get them on the right cars. Aside from the shot-peening, the SB and BB half-shaft assemblies were physically identical.