Engine Suffix and Corresponding Equipment Codes 1956-1991 � Lime Book

[Edward M.]

Hi James,

I agree - there doesn't seem to be a recognizable pattern...
I can't explain it though...it must be for specific configurations, different pulley sets, or some other critical element that applies to certain situations and not others...

That is correct. The engine codes were unique based on engine configurations for each model year. Every time an engine had to have a different part of configuration as a result of an option (or lack of option) it got a different engine code.

The one that also fascinates me are the 1966 engine codes with three characters where the last character is either an R or an H to represent either Rochester or Holley carburetor type to be installed. I spoke with a man that worked at the Flint engine plant in 1966, and he told me that the engine configuration difference between those two engines was the mounting studs for the carburetor for the Holley carb, and no mounting studs (I think I have that correct) for the Rochester carb. The Rochester carb was held on with bolts if I recall correctly, so they would be installed at the time the carb was installed.

And I am sure that even after five editions, there are still discrepancies in The Lime Book.

[Mark F.]

That is correct. The engine codes were unique based on engine configurations for each model year. Every time an engine had to have a different part of configuration as a result of an option (or lack of option) it got a different engine code.

The one that also fascinates me are the 1966 engine codes with three characters where the last character is either an R or an H to represent either Rochester or Holley carburetor type to be installed. I spoke with a man that worked at the Flint engine plant in 1966, and he told me that the engine configuration difference between those two engines was the mounting studs for the carburetor for the Holley carb, and no mounting studs (I think I have that correct) for the Rochester carb. The Rochester carb was held on with bolts if I recall correctly, so they would be installed at the time the carb was installed.

And I am sure that even after five editions, there are still discrepancies in The Lime Book.

Thanks, much Ed for your explanations above...and also for the work you did creating your book!

I wanted to buy a copy of your Lemon Book, too...but the NCRS Store says they are out of print.
I also looked on eBay, etc. and could not find one.
Is your Lemon Book available somewhere?

Also - I'd be happy to send you copies of my spreadsheets...let me know...shoot me an email on where to send them, if you wish...

Thanks again for this valuable reference document!

[Mark F.]

Just for reference the 1966 Corvette RPO list(attached below) includes RPO L88 and L89... Qty = 0. M22 Qty = 15. Rich PS Mark, Nice work on those files.

Hi Rich,

Good deal...looks like they were priming the pump for their eventual release in '67!
and thanks for the compliment...

[Edward M.]

[Richard M.]

Lemon Book is also out of print, but I will see what I can do about setting it up online like I did with the Lime Book.

Ed, What exactly does the Lemon book cover that's not in the Lime version?

Rich
PS That'd be great if you could do a Lemon book online version. Wonderful that you're sharing this great information.

[Patrick B.]

[Edward M.]

allengines_camaro-f_3-18.pdfallengines_camaro-f_3-18.pdf

[Mark F.]

A trivial observation- TI ignition is omitted from the description of the 1970 CTV code for the ZR1 LT-1.

• CGY 71 350 330 4B,4S(HD),ZR1 CO
• CKZ 72 350 255 4B,4S(HD),ZR1 CO
• ZSD 90 350 375 AC,MT,TPI,ZR1 CO
• ZSH 90 350 375 EAC,MT,TPI,ZR1 CO
• ZTK 91 350 375 MT,TPI,ZR1 CO

This is what is listed for the 1970 CTV suffix:

• CTV 70 350 370 4B,4S(HD) CO

Regarding TI:suffixrestrictedRegarding ZR1:

[Edward M.]

[Dan A.]

Mark,

The 1965 327/350 suffix code HU should have the power steering box checked. My '65 has 4 barrel carb, a/c, manual transmission, power brakes, and power steering.

Thanks,

James West

In support of the Lime Book (Thank You Ed McComas) the 1965 Technical Service Bulletin DR #690 titled 1965 Passenger Car and Truck Identification Information lists the HU suffix as Corvette L79 4 speed w/air conditioning. My Wife the Car Guy has a '65 HU engine car. As well optioned as it is, it does not have power steering. Although it does have power brakes.

[Edward M.]

[Joe L.]

That is correct. The engine codes were unique based on engine configurations for each model year. Every time an engine had to have a different part of configuration as a result of an option (or lack of option) it got a different engine code.

The one that also fascinates me are the 1966 engine codes with three characters where the last character is either an R or an H to represent either Rochester or Holley carburetor type to be installed. I spoke with a man that worked at the Flint engine plant in 1966, and he told me that the engine configuration difference between those two engines was the mounting studs for the carburetor for the Holley carb, and no mounting studs (I think I have that correct) for the Rochester carb. The Rochester carb was held on with bolts if I recall correctly, so they would be installed at the time the carb was installed.

And I am sure that even after five editions, there are still discrepancies in The Lime Book.

Ed------


There's a much more significant difference between the Holley and Q-Jet equipped engines than the carb mounting hardware. The Holley and Q-Jet equipped engines use completely different intake manifolds. So, for that reason alone, there would be different suffix codes.

[Edward M.]

[Joe L.]

Joe, I must be remembering what I was told incorrectly. I do specifically recall a discussion about carburetor mounting studs vs. carb bolts. Was there a non Corvette engine that used the same intake manifold.

Specifically, the 1966 327, 275hp engine, with powerglide, and installed in passenger cars (like Impalas). Did it use the same intake manifold regardless of carburetor type. Same question for the 1966 396, 325 hp, with powerglide or with TH400, and installed in passenger cars (like Impalas)?

Found it. 327, 275hp engines with intake manifold 3872783 could use either a Holley or a Rochester carb, depending on the application..

The engine code HCH or HCR would be the codes for this situation.

The engine codes IGH, IGR, IVH, IVR are the 396, 325 hp engines. In this case, I think they used manifolds that were marked either "Holley" or "Q-Jet" to distinguish then from each other.

Ed------


The GM manifold casting 3872783 will mount either a Holley, Carter AFB, or Rochester 4GC. However, it will not mount a Rochester Q-Jet (4MV).

Certain big block manifolds will mount a Holley carb and others will mount a Rochester Q-Jet. There is no big block manifold that will mount both types of carburetors unless an adapter is also used (adapters were NEVER used in PRODUCTION). Theoretically I suppose, the Holley carb manifolds would also mount a Carter AFB or Rochester 4GC but no such carbs were used on a PRODUCTION big block.

[Edward M.]