1967, 390 hp. Oil pressure gauge question

[Jack M.]

Re: 1967, 390 hp. Oil pressure gauge question

Jack-------


These look like specs that came directly out of the American Motor Vehicle Manufacturer's Association. As I have mentioned many times before, while one would expect these to be accurate, they are often not accurate.

For any given year, hydraulic lifter big blocks used the same oil pump as mechanical lifter big blocks EXCEPT for one thing------the pressure relief spring. This results in L-36, L-68, LS-4 and LS-5 having a 2000 rpm oil pressure of about 50 PSI and L-78, L-72, L-71, and LS-6 having a 2000 rpm oil pressure of about 75 psi. In this case, the specs shown are "sort of" accurate but they seem to imply that the 50-75 psi oil pressure range is applicable to all of the big block engines shown and that's definitely NOT accurate.

Hi Joe- Excellent info, but our specs only 'suggest' the gauge that was used on the production line. I believe the instrument cluster was an 'assembly' item... so we may never know the exact assembly instructions/procedures, for the given years.

As for the Info Kits, I did mention that there were some previous mistakes (thatz a given). I believe the images/data that I posted came from various sources... as they were in totally different sections. The images with the black rectangular 'LUBRICATION' specs come from the Passenger Car Specifications book that was put out by the Chevrolet Engineering Center (my 1966 book is dated Sept 1965 - similar to the Info Kits). The other images came from the AMA specs (I have three different dated AMA specs for 1966). I honestly don't know which came first... the chicken, or the egg. I'd speculate that the AMA specs came from Chevy supplied data... but I wouldn't bet the farm on it.

In addition, the Finger-Tip Facts for 1966 & 67 have a lubrication section for each engine... for the 390, both years list "Gear-type oil pump with fixed intake develops normal 50-75 p.s.i. oil pressure at 2000 engine rpm". This does NOT mean the data was absolutely korrect... and we know multiple changes have occurred during production. The books/data/specs were updated during the years... perhaps those changes took a while to be reflected in the instrument cluster assemblies. Highly original vehicles seem to tell the best story.

Respectfully,
Jack

[Ken A.]

Re: 1967, 390 hp. Oil pressure gauge question

That is actually not the case. 63 used 60 lb gauges in all engines early part of the year. 64 only had 80 lb gauges. And that 66 390 hp anomaly with 80 lb gauge and a hydraulic lifter engine. Take it to the bank.

This is the gospel. All other comments are just guesses.

[Stephen L.]

Re: 1967, 390 hp. Oil pressure gauge question

My April build 1967 427/390 has a 60# oil pressure gauge in the original cluster #6457985 LC

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

Hi Joe- Excellent info, but our specs only 'suggest' the gauge that was used on the production line. I believe the instrument cluster was an 'assembly' item... so we may never know the exact assembly instructions/procedures, for the given years.

As for the Info Kits, I did mention that there were some previous mistakes (thatz a given). I believe the images/data that I posted came from various sources... as they were in totally different sections. The images with the black rectangular 'LUBRICATION' specs come from the Passenger Car Specifications book that was put out by the Chevrolet Engineering Center (my 1966 book is dated Sept 1965 - similar to the Info Kits). The other images came from the AMA specs (I have three different dated AMA specs for 1966). I honestly don't know which came first... the chicken, or the egg. I'd speculate that the AMA specs came from Chevy supplied data... but I wouldn't bet the farm on it.

In addition, the Finger-Tip Facts for 1966 & 67 have a lubrication section for each engine... for the 390, both years list "Gear-type oil pump with fixed intake develops normal 50-75 p.s.i. oil pressure at 2000 engine rpm". This does NOT mean the data was absolutely korrect... and we know multiple changes have occurred during production. The books/data/specs were updated during the years... perhaps those changes took a while to be reflected in the instrument cluster assemblies. Highly original vehicles seem to tell the best story.

Respectfully,
Jack

Jack------


The way the information is formatted and scripted is exactly the way it was done in the AMA specs. And, yes, these specs were supplied to the AMA by GM/Chevrolet. The problem is also as you mentioned. There were several versions of the specs supplied at different times in the model year. Which version anyone has today is a guess. There was once a book published called "Corvette By The Numbers". This book contained nothing but copies of the AMA derived spec sheets and it was quite voluminous. However, most if not all the specs were from very early specs provided by GM/Chevrolet to the AMA. Some of the specs never actually got into PRODUCTION. So, the documents that seem authoritative may not be.

Also, the instrument cluster assembly supplied to St. Louis did include the gauges. The assembly was never available in SERVICE, only the individual components. However, I am virtually certain that the assemblies were made up of the same, exact part numbered components available in SERVICE.

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

That is actually not the case. 63 used 60 lb gauges in all engines early part of the year. 64 only had 80 lb gauges. And that 66 390 hp anomaly with 80 lb gauge and a hydraulic lifter engine. Take it to the bank.

Brian------

Yes, and that's pretty much how the P&A Catalogs have it, too


1963-----originally GM #5653118. Discontinued March, 1964 and replaced by GM #5654100. Both of these were 0-60# gauges. Was the 5654100 ever used in PRODUCTION? I doubt it. What's the difference in these? I do not know. The GM #5654100 was discontinued without supercession in April, 1974.

1964-----GM #5654175. This was a 0-80# gauge. It may also have been used in late 1963. The P&A catalogs provide no verification of this, though. It was discontinued without supercession in March, 1974.

1965-----early 1965 may have used GM #5655426. I have no information as to whether this gauge was a 0-60# or 0-80#, or exactly when, if ever, it was used in PRODUCTION. It was discontinued from SERVICE without supercession in November, 1964. So, if it was ever actually used in PRODUCTION I would opine that its use was extremely brief.

1965-67-----ALL engines with hydraulic lifters, GM #5654906. This was a 0-60# gauge. Discontinued without supercession October, 1976.

1965-67-----ALL engines with mechanical lifters, GM #5654626. This was a 0-80# gauge. Discontinued without supercession January, 1975.

In my opinion, any deviation from above seen on cars with known-original instrument clusters represents a factory anomaly.

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

I would not consider the parts book listings when determining originality on this subject. Where is the listing for the 1963 60 lb. gauge?
Parts books are for service replacement purposes. For that matter, the parts book lists one grille for 65-67, one gas door for 63-67, etc.
The oil gauge usage has been discussed at length over the years for those that care to look through the archives. I believe that every controversy has also been discussed through the years on our beloved cars. They are really old now!

Brian------

It depends on which edition of the P&A Catalogs one is referring to. I have found the P&A catalogs to be extremely accurate, almost astonishingly accurate. This is to be expected since they are derived from PRODUCTION information, including PRODUCTION information not found in the AIM's (or the version of the AIM's we have today). There were usually 3 or 4 editions of the P&A catalogs published during any particular model year. The most accurate information on original parts used in PRODUCTION is contained in the edition of the P&A catalog published within a few months after any particular car was manufactured. In the vast majority of cases, though, any P&A catalog published during the particular model year will have accurate information regarding the parts originally used. Subsequent editions of the P&A catalogs may or may not have accurate information regarding the parts originally used for any model year. The further out one gets in editions of the P&A catalogs, the less accurate they become regarding parts originally used.

Regarding the 1965 grille: in PRODUCTION that grille was made up at St. Louis from the individual components of that grille. This was probably done in an off-line assembly operation. However, the original 1965 grille as an assembly and all of the original components thereof were once available in SERVICE. The complete grille assembly was GM #3869148. But, it only lived a very short life. It was discontinued from SERVICE in July, 1966 and replaced by the 1966-67 grille, GM #3875746. The latter "lived on" in SERVICE for about 50 years. However, if one refers to any P&A catalog published after July, 1966, one is only going to see the 3875746 cataloged for all 1965-67 Corvette applications. That does not mean it was the original grille cataloged for all of those applications, though. By the way, the individual components of the 1965 grille lived on for various amounts of time after the grille assembly was discontinued and replaced for SERVICE.

As far as the C2 fuel doors go, the originals were once available in SERVICE.

1963------original fuel door assembly was GM #3797378 and was available in SERVICE. (Very late 1963 may have used GM #3846435 which was never available in SERVICE). GM #3797378 was discontinued in March, 1966 and replaced by GM #3858196 which was the 1965 fuel door. GM #3858196 was discontinued in December, 1966 and replaced by GM #3874528, the 1966 fuel door.

1964-----original fuel door was GM #3844040 and was available in SERVICE. The latter was replaced for PRODUCTION and SERVICE by GM #3852910. Supercession date for SERVICE was October, 1964. The GM #3852910 was discontinued from SERVICE in January, 1965 and replaced by GM #3858196, the 1965 fuel door assembly. As mentioned above, the 3858196 was discontinued in December, 1966 and replaced by GM #3874528, the 1966 fuel door assembly.

1965-----original fuel door was GM #3858196 and was available in SERVICE but only until December, 1966 when it was replaced by the GM #3874528, the 1966 fuel door assembly.

1966----original fuel door was GM #3874528. It remained available in SERVICE for almost 50 years.

1967-----original fuel door usage in PRODUCTION was governed by a chart, GM #3897371, which included individual part numbers for each body-colored door assembly. The body colored doors were never available in SERVICE. However, an apparently unpainted ("paint-to-match") but otherwise correct fuel door was available. This was GM #3901956. One would have to have acted fast to get this one, though. It was discontinued in December, 1966 and replaced by GM #3874528, the 1966 door assembly.

Once again, while all of the original fuel doors were once available in SERVICE (except the 1963 3846435 if it was ever actually used in PRODUCTION and the body-colored 1967 doors), if one refers to any P&A catalog published after December, 1966 one will not be so-informed.

[Jack M.]

Re: 1967, 390 hp. Oil pressure gauge question

Jack------


The way the information is formatted and scripted is exactly the way it was done in the AMA specs. And, yes, these specs were supplied to the AMA by GM/Chevrolet. The problem is also as you mentioned. There were several versions of the specs supplied at different times in the model year. Which version anyone has today is a guess. There was once a book published called "Corvette By The Numbers". This book contained nothing but copies of the AMA derived spec sheets and it was quite voluminous. However, most if not all the specs were from very early specs provided by GM/Chevrolet to the AMA. Some of the specs never actually got into PRODUCTION. So, the documents that seem authoritative may not be.

Also, the instrument cluster assembly supplied to St. Louis did include the gauges. The assembly was never available in SERVICE, only the individual components. However, I am virtually certain that the assemblies were made up of the same, exact part numbered components available in SERVICE.

Joe- Although the formats may be similar, the book references are definitely different. This is the book where the black/rectangular 'LUBRICATION SYSTEM' photo came from (it contains no AMA references). I was inkorrect earlier... although the lube page is dated Sept 1965, the book itself is a March 1966 Revision (some pages reflect date changes - there was no update to the lubrication data). Most of the photocopies I see have a 3-hole punch format (ie: the Info Kits)... this binder is very different looking (and quite comprehensive).

As for the instrument cluster assemblies, I believe they are labeled for specific uses... do we have any data/info on their individual components?

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

Joe- Although the formats may be similar, the book references are definitely different. This is the book where the black/rectangular 'LUBRICATION SYSTEM' photo came from (it contains no AMA references). I was inkorrect earlier... although the lube page is dated Sept 1965, the book itself is a March 1966 Revision (some pages reflect date changes - there was no update to the lubrication data). Most of the photocopies I see have a 3-hole punch format (ie: the Info Kits)... this binder is very different looking (and quite comprehensive).

As for the instrument cluster assemblies, I believe they are labeled for specific uses... do we have any data/info on their individual components?

Jack------


Well, if the spec sheet you previously posted came out of the reference you show above, then the AMA must have used an exact copy in their references. That's because the AMA specs I've seen (primarily in the book "Corvette By The Numbers") appear exactly as those you've shown from the reference pictured.

Yes, we have part numbers for the various original gauge components of the cluster assembly. I've presented those for the oil pressure gauge above. The others I could obtain but it takes a lot of time to dig them out and verify them so I won't be doing it now.

[Jack M.]

Re: 1967, 390 hp. Oil pressure gauge question

Jack------


Well, if the spec sheet you previously posted came out of the reference you show above, then the AMA must have used an exact copy in their references. That's because the AMA specs I've seen (primarily in the book "Corvette By The Numbers") appear exactly as those you've shown from the reference pictured.

Yes, we have part numbers for the various original gauge components of the cluster assembly. I've presented those for the oil pressure gauge above. The others I could obtain but it takes a lot of time to dig them out and verify them so I won't be doing it now.

Joe- My apologies for not being clearer. In my first post, there were FOUR (4) different images from the Info Kits (note the four thumbnails)... two come from one section, two from another. I believed the two with the black/rectangular 'LUBRICATION SYSTEM' came from the GM Spec book... the other two, were from the AMA section. I did initially mention they came from different sources/sections... perhaps that was overlooked.

In reference to the individual gauges, I was wondering about the company that assembled the clusters (guessing they weren't put together onsite). Their directions/instruction sheets could have been totally different... I doubt they were looking at a parts book (but I could be totally wrong). The parts book could have changed, but did their assembly instructions change at the same time?

All that is speculation on my part... yet there are some very knowledgeable people in this thread that seem to disagree on what oil gauge is actually found in highly original vehicles (especially in 1966). We owe it to ourselves to consider all avenues... none of the books we reference are perfect.

Your knowledge and assistance in this forum is invaluable. Out of respect to you, I will now bow out of this conversation. I had no intention to upset you... sorry if I did.

[Brian T.]

Re: 1967, 390 hp. Oil pressure gauge question

Joe,
I have not had the opportunity to look at the parts books between 1962 and 1967. No doubt you are the respected guru on the part system and we are grateful for your massive contribution to the hobby. I believe cluster configuration in question is the 1966 with the 427-390 engine option. This is a strange one indeed, using both the low RPM tach, and the 80 lb. oil gauge. (The 1967 hydraulic lifter 427 engines use the mid RPM tach.) The only other configuration like this would be the 327-250, and 327-300 1964 cars. This of course is because the 1964 did not have a 60 lb. oil gauge.
Through the years, you can get a sense when a cluster is all original. I have seen many 1966 clusters just like this and never a variance on known original cars. Included are cars that I have personal knowledge of their history.
When accepting units for restoration, we always request owners year and HP. This is to be certain that the customer ends up with what would be correct for their car. I need to recall the broadcast code or letter code for this one and do not have it handy. If memory serves me correctly the label would read LD.
I have been compiling a list of variances on production dash clusters for quite a while. 1965 model year stands out as one with many small variances. These small variations help to determine if a cluster has been apart and subjected to changes. 1965-1967 also used 2 small self adhering sponge like strips between the small gauges on each side. Seldom are these intact.
To sum this up, all 427 equipped 1966 cars would have the 80 lb. oil gauge. Of course, there could be an original car or two that does not, but I doubt it. It would be of interest to see what the 1966 parts book shows for the tachometer on the 390 HP cars.
It would be great if John H. has any additional input on the subject. Also would be helpful for owners of these cars would contribute.

Brian

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

Joe- My apologies for not being clearer. In my first post, there were FOUR (4) different images from the Info Kits (note the four thumbnails)... two come from one section, two from another. I believed the two with the black/rectangular 'LUBRICATION SYSTEM' came from the GM Spec book... the other two, were from the AMA section. I did initially mention they came from different sources/sections... perhaps that was overlooked.

In reference to the individual gauges, I was wondering about the company that assembled the clusters (guessing they weren't put together onsite). Their directions/instruction sheets could have been totally different... I doubt they were looking at a parts book (but I could be totally wrong). The parts book could have changed, but did their assembly instructions change at the same time?

All that is speculation on my part... yet there are some very knowledgeable people in this thread that seem to disagree on what oil gauge is actually found in highly original vehicles (especially in 1966). We owe it to ourselves to consider all avenues... none of the books we reference are perfect.

Your knowledge and assistance in this forum is invaluable. Out of respect to you, I will now bow out of this conversation. I had no intention to upset you... sorry if I did.

Jack------

No need to bow out. In fact, I don't know what gave you the idea I was upset. I'm not upset in any way.

[Joe R.]

Re: 1967, 390 hp. Oil pressure gauge question

Fellow NCRS Members,

We have all heard the statement that "My Corvette is Original for I bought it from the Original Owner" a thousand times!

The fact is that whether it was Delco or other suppliers the idea was to ship the goods and the Union Workers at St. Louis pushed them down the line and filled the holes with what was available. Not slamming Union Workers as I was proud to be a steelworker and cashed United States Steel's checks.

When items were in the boxes, barrels or on the shelf they were installed. Examples of this would be jacks and hoods!

As we all have said or should have, "There ain't no perfect Corvette".

Donations of knowledge and expertise on this forum is a benefit of membership.

Enjoy!

JR

[Ronald L.]

Re: 1967, 390 hp. Oil pressure gauge question

The P& A books were written after the model year - a 70s book, likely will not be correct, it will have consolidated usages.

What you need to refer to to get the accurate picture is the AIM, that instructed the plant what to install and when. 66 427-390HP got an 80# gauge, with no changes during the model year. The info is all there to get the next JG version correct, 66 pg F365, and 67 calls out the details inclusive of changes on A6 G366

[Joe L.]

Re: 1967, 390 hp. Oil pressure gauge question

The P& A books were written after the model year - a 70s book, likely will not be correct, it will have consolidated usages.

What you need to refer to to get the accurate picture is the AIM, that instructed the plant what to install and when. 66 427-390HP got an 80# gauge, with no changes during the model year. The info is all there to get the next JG version correct, 66 pg F365, and 67 calls out the details inclusive of changes on A6 G366

Ronald------


P&A catalogs were published after the model year but they were also published at the beginning of the model year and 2 or 3 times during the model year. For example, the P&A catalog for the 1963 model year was first published in October, 1962.

The part numbers for the instrument panel gauges were not specified in the AIM's because the gauges were part of the instrument panel assemblies. The instrument panel assemblies were never available in SERVICE and, thus, are not to be found in P&A catalogs. The part numbers for the individual gauges are only found in the P&A catalogs. However, the part numbers for the speedometer and tachometer are often found on the broadcast label on the rear of the instrument panel assemblies.

[Gary J.]

Re: 1967, 390 hp. Oil pressure gauge question

Hope the ones working on the new 1966 Judging Manual are paying attention to this thread and will make the correction in the new manual.