3878299

[Loren L.]

Need an ID on a Winters foundry aluminum 4 bbl intake (BBC) with the above casting # and a casting date of 9.25.65. Also has a stamping of
"BW 23R 1" in two places, along with a stamping of "H YUNICK" - THAT part I can ID! ideas?? Thanks.

[Joe L.]

Re: 3878299

Loren-----

I've meant to get back to you on this one, but I've been trying to come up with some more (and definitive) information. So far, this is what I can tell you:

GM #3878299 was a part number that was NEVER used in PRODUCTION and it was, as far as I can tell, never available in regular SERVICE. However, due to its part number, we know that it was not a proto-type or experimental piece. The part number infers a 1965 or 1966 release which is, of course, consistent with the casting number.

In general, GM SERVICE part numbers for intake manifolds are not the same as the casting numbers which appear on the manifolds. However, I've cross-checked every SERVICE part number of the period and I can find none that are "unaccounted for" as far as correlating casting number.

Given the inscription on the manifold, I strongly suspect that this was a "SERVICE" item that was not available through regular GM parts channels. I suspect that it was one of the "back door" items that could be obtained if you were a "big-time racer" with established credentials and/or other "friends of the GM hierarchy".

It also remains possible that it was an over-the-counter item that was available through regular GM SERVICE parts channels (although this particular one, apparently, didn't have that sort of origin). The problem is that I have no records of PART numbers for these very early, SERVICE-ONLY, hi-performance parts. So, I can't correlate casting numbers for these items with SERVICE part numbers for further research. Frankly, though, I don't think that this manifold falls into the category of a generally available, SERVICE-only item.

How does this manifold compare in configuration to the 1965 L-78 manifold, GM casting #3866963 or the 66 L-72 manifold, GM casting #3885069?

[Mike M.]

Re: 3878299

loren is it a Mark III intake? never seen one but if ole smokey had it , it probably got in his back door from GM.let us know if and when you figure it out. regards, mike

[Franz E.]