Stamp pad help

[Paul J.]

Re: Stamp pad help

Here's another source. http://www.idavette.net/facts/66.htm and http://www.motorera.com/corvette/1960/vet66.htm

Jim, that Idaho Corvette page is great, but I've already found an error in the 64 production data. I wonder how accurate the rest of this information is.

Paul

[Jim D.]

Re: Stamp pad help

Jim, that Idaho Corvette page is great, but I've already found an error in the 64 production data. I wonder how accurate the rest of this information is.

Paul

There are multiple mistakes in the NCRS Tech & Judging Guides as well. What's your point?

[Michael J.]

Re: Stamp pad help

Interesting there are so many conflicting definitions of the codes. My '66 L79 has an HT code, it came with P/S (invoice, POP, and window sticker docs), but no A/C or any other power options and has the M-20. Maybe the codes are just not well understood???

[Joe R.]

Re: Stamp pad help

I have a that I am looking at 66 300 hp,/fact a/c,p.s.,p.b. and the stamp pad reads FOIO 3 HP?? Everything I can find on this it should be L79 350h.p. engine. The valve covers are painted and have 300hp decals. Is it a 350 with the wrong valve covers? Or am I misssing something? Thanks Tom #41491

Hi Tom:

Per the 1967 NCRS JG (the only one I have on hand), the HP code was used for an L79 4-speed that had A/C *and* PS. There has been some discussion on the TDB about why this configuration had its own suffix, considering that both A/C and PS were installed at St. Louis. A unique engine suffix implies that there was something different about the engine assembly that Flint delivered to St. Louis.

Based on my previous research on pulley configurations, it is my belief that what was different about the Flint HP configuration was that the water pump hub spacing was set to 5-9/16 inches to work properly with the standard-groove pulleys used on L79 A/C cars with PS. All other L79 configurations were equipped with deep-groove pulleys and used a 5-11/16 inch spacing on the water pump flange.

So, I think the HP code that you see on this car is correct.

[Joe R.]

Re: Stamp pad help

Hi Tom:


(snip)...So, I think the HP code that you see on this car is correct.

Hi Tom:

I should have said, "correct for an L79 with AC and PS."

Note that my comments are for 1967, not the 1966 that you are looking at. I do not have data for 1966.

It would be unusual for someone to dress an L79 like a base 300 motor (the opposite change was very popular back in the day). There is no easy way to confirm this, since the only hard-to-change differences were internal to the engine and heads. Externally, though, the differences were the valve covers, intake manifold, water pump, balancer, timing chain cover, and threaded crank snout for a balancer retention bolt.

If you check all of these components, which which way does the evidence point? It's not conclusive, but worth checking.

[Jim D.]

Re: Stamp pad help

Joe,
Since there is a difference in codes between 65 & 66, I doubt the 67 info. is any help. He posted above that the car has a 5500 redline. That indicates a 300HP.

Tom Hendricks,
Obviously our Blackbooks appear different for some reason. You don't say the source of your other pics. Can you post where in your Noland Adams book that says different than what I posted?

Granted valve covers and various bolt ons are easy to change but why would someone put a low RPM tach in it if it was actually a 350HP motor? Inquiring minds want to know.

[Tom H.]

Re: Stamp pad help

Joe,
Since there is a difference in codes between 65 & 66, I doubt the 67 info. is any help. He posted above that the car has a 5500 redline. That indicates a 300HP.

Tom Hendricks,
Obviously our Blackbooks appear different for some reason. You don't say the source of your other pics. Can you post where in your Noland Adams book that says different than what I posted?

Granted valve covers and various bolt ons are easy to change but why would someone put a low RPM tach in it if it was actually a 350HP motor? Inquiring minds want to know.

Hi Jim !

My other books I have in the office are the NCRS pocket guide, Alan Colvin's Corvette by the numbers and the Cars and Parts catalog of Corvette ID #'s. I always have a current Black Book in my desk as well. My Noland Adams book is at home and will double check that info tonight for you.

[Michael J.]

Re: Stamp pad help

Dobbins' Vette Views fact book is not much help. It shows HP to be "Power Steering", whereas my engine code (HT) just shows "Special High Performance".

[Joe R.]

Re: Stamp pad help

Joe,
Since there is a difference in codes between 65 & 66, I doubt the 67 info. is any help. He posted above that the car has a 5500 redline. That indicates a 300HP.

Granted valve covers and various bolt ons are easy to change but why would someone put a low RPM tach in it if it was actually a 350HP motor? Inquiring minds want to know.

Hi Jim:

I agree that 1967 codes *might* differ from 1966 codes, which is why I included that caveat. However, several of the sources that have been referenced in this thread show that for 1966, the HP code is for an L79 with A/C and PS, same as 1967.

Since making my earlier post, I dug out the 2002 Black Book and the 1999 NCRS spec guide that I have on file. Both say the for 1966, the HP code is for an L79 with A/C and PS. I think both of these are referenced earlier in this thread.

The main point of my post was to address why GM would even bother creating the HP code in the first place, and to clarify that any L79 with both A/C and PS will have a unique engine suffix that differs from what most L79 engines have.

Regarding whether the engine block in question is a 300 HP or 350 HP, I don't think the determination can be made based on any single, observable external factor, whether it be valve covers or tach redline. A lot can happen to a car in 43 years.

We don't even know, at this point, whether the block in question has the same VIN as the car, or whether the pad appears original.

So, my first step would be to look at all the known external differences between the 300 and 350 horse configurations, to see which way the evidence points.

My second step would be to carefully examine the pad to see if it looks original.

If the engine is completely dressed as a 300 HP, the tach has a 5500 redline, and the pad appears to be original to the car, we have something quite interesting.

[Dan A.]

Re: Stamp pad help

Once again, I think it would be far more helpful to reduce the speculation if the original poster would supply all the pertinent numbers. Both complete stamped numbers from the pad and the casting number and casting date.

[William C.]

Re: Stamp pad help

Both 1971 and 1982 GM parts books show only the notation "power Steering" for the '66 "HP" code. FWIW

[Tom H.]

Re: Stamp pad help

Once again, I think it would be far more helpful to reduce the speculation if the original poster would supply all the pertinent numbers. Both complete stamped numbers from the pad and the casting number and casting date.

Daniel:

Even if the OP provides all of the information on his car, it still leaves us with inconsistent information from publication to publication on this suffix ??

[Tom S.]

Re: Stamp pad help

Thank you all very much for your help. The engine pad does have the correct serial # matching the car. The owner says the pad looks original to him. I am going to look at the car Friday.I am still very confused, but I will check casting #'s dates, and everything else that is visible. Thanks again to all who helped. I will post more when I find out what is going on.

[Paul J.]

Re: Stamp pad help

There are multiple mistakes in the NCRS Tech & Judging Guides as well. What's your point?

No point, just an observation. Apparently, you're saying you can't trust NCRS publications either. I thought that the errors in the NCRS Guides were matters of interpretations of originality. The Idaho page listed L84 with an automatic transmission.

I have contacted CV World about it.

[Tom H.]

Re: Stamp pad help

You can surely trust NCRS publications, but, as with all printed material, errors occur. They can be flat out errors or typos. They happen. Period. That's whay it is best to use multiple publications as well as your personal experience. The NCRS has great material though that is generally accepted as the best information currently available. JMO !