Looking for C2 part number help.

[William V.]

[Clem Z.]

Re: Looking for C2 part number help.

346 cam is the 30/30 cam and the 178 is the LT-1 cam

[Joe L.]

Re: Looking for C2 part number help.

Bill-----

The GM #3972178 camshaft was originally used for 1970 and later LT-1 applications. However, it later replaced, for SERVICE, the GM #3849346 camshaft. The 3849346 was the camshaft originally used in PRODUCTION for 1964 and 1965 Corvettes with L-76 and L-84.

In reproduction, you can obtain either the original 3849346 OR the GM #3972178. I recommend going with the latter.

The GM #3817684 sleeve is discontinued and has been for quite awhile. You can't use the earlier or later sleeves, either, if you have a 63-65 differential unit. However, I'm pretty sure that these pieces are still available in the aftermarket. I'd recommend calling Charlie Smith at Charlie's Speed Shop in Champaign, IL (I don't have his number handy but I'm sure it's available). Also, I would expect that you could get one through Tom's Differential's of Paramount, CA (www.tomsdifferentials.com)

[Joe R.]

Re: Looking for C2 part number help.

Bill,

The number for the crush sleeve is indeed 3817864 and is used only in the 63-64 Dana series carriers. The later Eaton series carriers (65-66)used part number 3954483. If you are lucky enough to have the later Eaton series carrier you have no problem. The general still stocks the crush sleeve for the Eaton carriers.

Regards,

JR

[Joe L.]

Re: Looking for C2 part number help.

Joe-----

I'm not so sure about that. I don't think that the crush sleeve is related to the installed positraction unit (Dana or Eaton). It is true, of course, that 63-64 originally used the Dana posi and many have been retroffitted with Eaton by now. However, 63-64 (and, possibly 65, also) also used a different main case than later units. They also used a different design pinion gear shaft. The crush sleeve difference is related to the case and pinion gear shaft differences. So, even if the positraction carrier unit is changed, that doesn't affect the main case or pinion gear and the 63-64 crush sleeve must still be used.

Of course, if the entire unit is a 66+ style (as the complete units are interchangeable among 63-79), then it will require the later crush sleeve. However, if the 63-64 style sleeve is what you take out, that's what you've got to put back in regardless of whether the posi unit is the original style, or not.