1967 Intake #3883948

[Michael S.]

I have a 1967 Intake #3883948 Date D187, cast iron, spreadbore. Was this ever used on Corvettes? The NCRS Spec. Book says it was used late 1967. Did the 427 go from a holley to a Quadra-jet then? Thanks, Michael

[Wayne M.]

Re: 1967 Intake #3883948

No, per A. Colvin's book. "3883948 Was used on '66 thru '68 on a mix of passenger, Chevelle, Camaro (depending on MY). Has word "Q-jet" cast into top for quick identification"

However, a similar cast # 3886948 WAS used on '66 and '67 L36 Corvettes, as well as other '65 thru '67 Chevrolet autos. Was a square bore for Holley carbs and has a "holley" casting for identification.

[Scott S.]

Re: 1967 Intake #3883948

No, per A. Colvin's book. "3883948 Was used on '66 thru '68 on a mix of passenger, Chevelle, Camaro (depending on MY). Has word "Q-jet" cast into top for quick identification"

However, a similar cast # 3886948 WAS used on '66 and '67 L36 Corvettes, as well as other '65 thru '67 Chevrolet autos. Was a square bore for Holley carbs and has a "holley" casting for identification.

Wayne,

I was trying to figure out whether I have the "early" L79 intake manifold or the "late" (67P&A says 3888884 USE 3893594, 7-66), and what the difference might be. The underside of mine is dated 11.28.66.

In the process I found the discussion of the late 1967 L36 intake manifold, with casting number 3883948. There is a post in the archives saying it has "Holley" cast on it, several Threads seem to affirm that it was used on late '67 L36 Corvettes, it is mentioned in the NCRS Specifications Guide, the 67JG and in Adams.

I couldn't find your reference in Colvin's book, but I only have "Corvette by the Numbers". Were you referencing Colvin's "Chevrolet by the Numbers: 1965-69"?

Has this issue now been settled that casting 3883948 was not used on late '67 L36 engines, or is it contended that there are 3883948 castings with "Holley" cast on the outside and other intakes with the same 3883948 casting number, but with "Q-Jet" cast on the outer surface?

[John H.]

Re: 1967 Intake #3883948

Has this issue now been settled that casting 3883948 was not used on late '67 L36 engines, or is it contended that there are 3883948 castings with "Holley" cast on the outside and other intakes with the same 3883948 casting number, but with "Q-Jet" cast on the outer surface?

Scott -

Don't know where the issue stands on when (or if) the 948 manifold was used, but I can't imagine that casting number being usable with either a Holley or a Q-Jet; the Holley is a square-bore and the Q-Jet is a spread-bore, and the castings for each type are completely different. IF the 948 was used in late '67, it was used with a Holley; the Q-Jet didn't show up on Corvettes until 1968.

[Wayne M.]

Re: 1967 Intake #3883948

....I was trying to figure out whether I have the "early" L79 intake manifold or the "late" (67P&A says 3888884 USE 3893594, 7-66), and what the difference might be. The underside of mine is dated 11.28.66.

Scott -- In that post from two years ago I was using my Colvin Chevrolet-by-the-numbers '65-9 (which includes Corvette). Today, I can find no reference to those two casting numbers for '67 aluminum small block manifolds. and I don't have the judging manuals for '66 or '67 to check what is said there.

..... In the process I found the discussion of the late 1967 L36 intake manifold, with casting number 3883948. There is a post in the archives saying it has "Holley" cast on it, several Threads seem to affirm that it was used on late '67 L36 Corvettes, it is mentioned in the NCRS Specifications Guide, the 67JG and in Adams. Has this issue now been settled that casting 3883948 was not used on late '67 L36 engines, or is it contended that there are 3883948 castings with "Holley" cast on the outside and other intakes with the same 3883948 casting number, but with "Q-Jet" cast on the outer surface?

Like John H. says, the 3866948 is the cast iron Holley square bore manifold, and was used on L36 Corvettes in 1966 and 1967. The 3883948 is the cast iron Q-Jet spread bore manifold, used on '66 Passenger (late, unverified) and '66-7 Chevelle, and '67-68 Pass. Camaro, Chevelle; --- no Corvettes. Above paragraph per Colvin book. Too many BB manifolds ending in ...948.

[Scott S.]

Re: 1967 Intake #3883948

John and Wayne,

After doing some searching online, all of the casting number databases (e.g., http://www.nastyz28.com/bbcmenu.php) I checked show Intake Manifold GM 3883948 is for a Q-Jet carburetor. I have found many photos of 3883948 cast iron intake manifolds (eBay has twelve different examples currently listed), with the casting number clearly visible, and every one of them is for a Quadra-Jet carburetor, with a raised "Q JET" embossed on the outer surface and also clearly visible. Not a single example for a Holley so far.

At this point, it looks like the JG and the Spec Guide are in error on this point, unless:

A) the 3883948 casting was altered to use a Holley carburetor without changing the casting number, for what would have been a small production run, since Q-Jet examples are plentiful and no examples designed for a Holley have turned up yet,

or

B) a small number of very late 1967 L36 Corvettes escaped St. Louis with 1968 Corvette Quadra-Jet carburetors sitting on top of 3883948 intake manifolds which then were not used on 1968 Corvettes anyway.

Which would probably make it more rare than an L88 with M35 and C60.

An old post over on the CF seemed to imply photos (no longer viewable) of an April 28, 1967 survivor with the 3883948 intake manifold. I asked if the photos could be re-posted.

[Joe L.]

Re: 1967 Intake #3883948

John and Wayne,

After doing some searching online, all of the casting number databases (e.g., http://www.nastyz28.com/bbcmenu.php) I checked show Intake Manifold GM 3883948 is for a Q-Jet carburetor. I have found many photos of 3883948 cast iron intake manifolds (eBay has twelve different examples currently listed), with the casting number clearly visible, and every one of them is for a Quadra-Jet carburetor, with a raised "Q JET" embossed on the outer surface and also clearly visible. Not a single example for a Holley so far.

At this point, it looks like the JG and the Spec Guide are in error on this point, unless:

A) the 3883948 casting was altered to use a Holley carburetor without changing the casting number, for what would have been a small production run, since Q-Jet examples are plentiful and no examples designed for a Holley have turned up yet,

or

B) a small number of very late 1967 L36 Corvettes escaped St. Louis with 1968 Corvette Quadra-Jet carburetors sitting on top of 3883948 intake manifolds which then were not used on 1968 Corvettes anyway.

Which would probably make it more rare than an L88 with M35 and C60.

An old post over on the CF seemed to imply photos (no longer viewable) of an April 28, 1967 survivor with the 3883948 intake manifold. I asked if the photos could be re-posted.

Scott------


A) Absolutely NEVER occurred.

B) Absolutely NEVER occurred.

[Patrick B.]

Re: 1967 Intake #3883948

"Absolutely never" is a pretty strong assertion. I bought an L36 red 67 coupe (VIN 14900) in Texas in 1988 from a young man who used it as his daily driver. All the parts on the car looked original, and the owner was not a restorer. The car had had some body damage repaired and was repainted, otherwise everthing was original including the interior and the engine. The grain and stamping on the pad were undoubtedly original (T0307IL, casting B-22-7). The heads were also cast around B-15-7. It had the 3883948 manifold and a quadrajet on it. I bought a Holly manifold and a 3811 carb for it since I figured the Quadrajet could not be original. Before I got around to installing them, I notice that the casting date of the manifold was also in February 67, lining up perfectly with the other engine castings on an engine that had no signs of being rebuilt. I believe it also had an original looking steel fuel line. I don't know if the carb was dated in 67 because I was only knowledgeable about Holly carbs. Although it did not conform to was was supposed to be on a 67 L-36, it looked so original that I could not bring myself to change it. I sold the car a few years later to a well known dealer at Carlisle who was looking for big block cars with original engines who also seemed to think the manifold was original.

[Scott S.]

Re: 1967 Intake #3883948

"Absolutely never" is a pretty strong assertion. I bought an L36 red 67 coupe (VIN 14900) in Texas in 1988 from a young man who used it as his daily driver. All the parts on the car looked original, and the owner was not a restorer. The car had had some body damage repaired and was repainted, otherwise everthing was original including the interior and the engine. The grain and stamping on the pad were undoubtedly original (T0307IL, casting B-22-7). The heads were also cast around B-15-7. It had the 3883948 manifold and a quadrajet on it. I bought a Holly manifold and a 3811 carb for it since I figured the Quadrajet could not be original. Before I got around to installing them, I notice that the casting date of the manifold was also in February 67, lining up perfectly with the other engine castings on an engine that had no signs of being rebuilt. I believe it also had an original looking steel fuel line. I don't know if the carb was dated in 67 because I was only knowledgeable about Holly carbs. Although it did not conform to was was supposed to be on a 67 L-36, it looked so original that I could not bring myself to change it. I sold the car a few years later to a well known dealer at Carlisle who was looking for big block cars with original engines who also seemed to think the manifold was original.

Patrick,

Thanks for posting, very interesting. Assuming that your car's intake and carburetor were original, what set of circumstances could lead to such an anomaly?

For example, if there was a shortage of the regular 3866948 intake manifold, what would they do? Can't stop the assembly line. Did the St. Louis assembly plant have easy access to 3883948 intake manifolds and 1968 model year Corvette QuadraJet carburetors? If the St. Louis plant had access to these parts, would the 3883948 intake manifold + QuadraJet carburetor be the best available option in the case of a shortage of standard production intake manifolds, or were there other better options they could have used?

Edit: I forgot the intake manifolds were installed at Tonawanda, not St. Louis, so that changes things...

[Joe L.]

Re: 1967 Intake #3883948

"Absolutely never" is a pretty strong assertion. I bought an L36 red 67 coupe (VIN 14900) in Texas in 1988 from a young man who used it as his daily driver. All the parts on the car looked original, and the owner was not a restorer. The car had had some body damage repaired and was repainted, otherwise everthing was original including the interior and the engine. The grain and stamping on the pad were undoubtedly original (T0307IL, casting B-22-7). The heads were also cast around B-15-7. It had the 3883948 manifold and a quadrajet on it. I bought a Holly manifold and a 3811 carb for it since I figured the Quadrajet could not be original. Before I got around to installing them, I notice that the casting date of the manifold was also in February 67, lining up perfectly with the other engine castings on an engine that had no signs of being rebuilt. I believe it also had an original looking steel fuel line. I don't know if the carb was dated in 67 because I was only knowledgeable about Holly carbs. Although it did not conform to was was supposed to be on a 67 L-36, it looked so original that I could not bring myself to change it. I sold the car a few years later to a well known dealer at Carlisle who was looking for big block cars with original engines who also seemed to think the manifold was original.

Patrick-----


If someone shows me an original 1967 Protecto-Plate that indicates a 1967 Corvette was equipped with a Rochester carb (i.e. "R" code on plate), I'll believe it was built with a Q Jet.

As far as the manifold date code goes, the 66-67 Q-Jet manifold was manufactured fro a relatively short period of time. Thus, about 25% of the manifolds ever made would be NCRS date-correct for any particular 66-67 car.

[John H.]

Re: 1967 Intake #3883948

Assuming that your car's intake and carburetor were original, what set of circumstances could lead to such an anomaly?
If the St. Louis plant had access to these parts, would the 3883948 intake manifold + QuadraJet carburetor be the best available option in the case of a shortage of standard production intake manifolds, or were there other better options they could have used?

Scott -

Building a '67 L-36 with a Q-Jet intake and carburetor would have required LOTS of parts specific to that application that were NOT at St. Louis, as that combination was never released for '67 production. I was at St. Louis for the '67 buildout, and never saw (nor heard of from the plant folks) ANY '67 Corvette built with a Q-Jet; any such combination must have been added by someone after the car was built.

[Patrick B.]

Re: 1967 Intake #3883948

Joe: I'm sure you're right, but it was the oddest thing that a car that was completely unmodified in all other respects (except perhaps the side pipes) would have a quadrajet manifold dated between the block and head casting dates. By the way, it was the best running old Corvette I've ever had. I bought it in West Texas with the help of Ronnie Raines, who is one of our TDB participants, and drove it home to the D.C. area the next day without a second thought.

[Joe L.]

Re: 1967 Intake #3883948

Joe: I'm sure you're right, but it was the oddest thing that a car that was completely unmodified in all other respects (except perhaps the side pipes) would have a quadrajet manifold dated between the block and head casting dates. By the way, it was the best running old Corvette I've ever had. I bought it in West Texas with the help of Ronnie Raines, who is one of our TDB participants, and drove it home to the D.C. area the next day without a second thought.

Patrick------

Yes, it is odd that the manifold date is consistent with the rest of the engine and the car's build date. But, that could happen just as a chance occurrence. Plus, as I mentioned, that manifold was not manufactured for a very long period of time so I expect that most all of them have 1966 or 1967 dates.

One more thing I should have mentioned: the engine suffix code defines a certain engine configuration. Usually, even very small differences will result in a different suffix code. This is necessary so that assembly plant personnel can quickly identify the exact engine needed for a particular application. For the most part, the assembly plants did not even have the parts on site which would be necessary to make a conversion if the engine was not completely compatible for the intended installation. For example, an "IM" coded included only the AIR pump bracket and exhaust manifolds with AIR fittings. Otherwise, it was identical to the "IL" coded engine. The "IL" (and "IM") coded engine included a manifold for a Holley carburetor. If there had been an L-36 which was equipped with an intake manifold for a Rochester carburetor, I'm absolutely sure that such an engine would have carried a suffix code other than "IL" (or "IM"). However, I know of no such suffix code for a Rochester-equipped L-36. Since you mentioned that this engine had an "IL" code, I'm very confident that it was originally equipped with a Holley carb.

As far as the engine running well, that's exactly what I would expect since a Rochester Q-Jet is a better street carburetor than a Holley. Far better in my opinion. In fact, that's probably exactly why someone changed it from the Holley to the Q-Jet in the first place.

[Keith B.]

Re: 1967 Intake #3883948

GM built a lot of 396 Chevelles and Impalas with a Q-jet. So I am sure it was not hard for someone to change it out

[Joe L.]

Re: 1967 Intake #3883948

GM built a lot of 396 Chevelles and Impalas with a Q-jet. So I am sure it was not hard for someone to change it out

Keith-----


Yes, and the entire package could have been transferred, including manifold, carb, and fuel line.