Base Engine Designation

[Mark E.]

Are RPO engine designations only for optional engines?

For example, did the 250hp base engine for 63-65 have an RPO designation? L-something...

The 300 hp engine for 63-65 is L75. Did Chevrolet use that designation when it was used for the 66-68 base engine?

The base engine for 69-80 was L48, so it had an RPO even though it wasn't an option.

[Joe L.]

Re: Base Engine Designation

Are RPO engine designations only for optional engines?

For example, did the 250hp base engine for 63-65 have an RPO designation? L-something...

The 300 hp engine for 63-65 is L75. Did Chevrolet use that designation when it was used for the 66-68 base engine?

The base engine for 69-80 was L48, so it had an RPO even though it wasn't an option.

Mark------


The base engine for at least 1969-70 was never designated L-48. In the vernacular it was referred to as that but that was never a Chevrolet designation. When installed in other Chevrolet vehicles as an upgrade from the base engine, essentially the same engine as Corvette was designated L-48.

RPO = Regular Production Option. Base engines were never regarded as an "option".

[Larry E.]

Re: Base Engine Designation

Mark------



RPO = Regular Production Option. Base engines were never regarded as an "option".

Hay Joe: How would you describe the 69 Camaro Z28 engine (302 C/I)?? Is this a "base engine"? Larry

[Joe L.]

Re: Base Engine Designation

Hay Joe: How would you describe the 69 Camaro Z28 engine (302 C/I)?? Is this a "base engine"? Larry

Larry------


It was part of the Z-28 option package and not available separately.

[Jack M.]

Re: Base Engine Designation

Mark- From a few of the C2 Dealer Order Forms:

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[Tom R.]

Re: Base Engine Designation

What's missing from this discussion and posts is the transition of management of the St Louis Assembly Plant from the Chevrolet Motor Division to the General Motors Assembly Division in 1972-73. This is when we see the landscape style buildsheet with both RPOs and broadcast codes introduced. Take a look at a later C3 Corvette Parts & Illustration Catalog and you'll find equipment, like engines designated an RPO. Remember, Corvette production did not remain the same in later Corvette generations as that of the C2 generation, a myth that persists.

During this period (GMAD management), base equipment was designated an RPO when accompanied with other options but remained the default option. Take for example emission systems. As they acquired more components/systems and were further delineated, such as California (YF5/NB2) and later high-altitude (NA6), the base system (Federal) was identified as RPO NA2 and called out on buildsheets.

To illustrate, I've attached a 77 buildsheet where you'll see the base engine (L48), base transmission (M20) and base emissions (NA2) RPOs called out.

buildsheet_77.jpg

[Duke W.]

Re: Base Engine Designation

Are RPO engine designations only for optional engines?

For example, did the 250hp base engine for 63-65 have an RPO designation? L-something...

The 300 hp engine for 63-65 is L75. Did Chevrolet use that designation when it was used for the 66-68 base engine?

The base engine for 69-80 was L48, so it had an RPO even though it wasn't an option.

Since the 327/250 was base equipment on Corvette it had no associated option number.

However, on other Chevrolet models the base engine may have been the I-6 or a 283 with the two 327s being optional. So for other Chevrolet models where the 327/250 was optional there would be an associated RPO, but I don't know what it is.

When the 327/300 became the base Corvette engine for '66 it retained the L-75 RPO designation for other Chevrolet models where it was optional.

Duke

[Harry S.]

Re: Base Engine Designation

This is from a 250hp 63. The engine is identified.

30867S113356 for email.jpg

[Frank D.]

Re: Base Engine Designation

Interesting Harry, that doc cites both a hardtop and soft top...IIRC, you get one or the other with the car purchase and if you choose to add the one you did NOT get that was an option (and extra money) - correct ? (Sorry for the slight off-topic)..

[Harry S.]

Re: Base Engine Designation

Interesting Harry, that doc cites both a hardtop and soft top...IIRC, you get one or the other with the car purchase and if you choose to add the one you did NOT get that was an option (and extra money) - correct ? (Sorry for the slight off-topic)..

Frank, correct. You had to pay for the second top. If you pull the inside trim from the hardtop, you will find the color written, Black in my case, the top was to be painted and the job number. This is one way to tell if the top was original to the car.

[Jack M.]

Re: Base Engine Designation

Since the 327/250 was base equipment on Corvette it had no associated option number.

However, on other Chevrolet models the base engine may have been the I-6 or a 283 with the two 327s being optional. So for other Chevrolet models where the 327/250 was optional there would be an associated RPO, but I don't know what it is.

When the 327/300 became the base Corvette engine for '66 it retained the L-75 RPO designation for other Chevrolet models where it was optional.

Duke

Duke- These are the Power Teams for a full size Chevy in 1963. The 250HP was an L30:

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1963_Chevrolet_Power_Teams-01.jpg
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[Tom R.]

Re: Base Engine Designation

As Jack points out in 68, base motor was L30 for a 327/250
In 69-72, RPO for base was ZQ3 for a 350/300
In 1973, base became the L48

[Duke W.]

Re: Base Engine Designation

Interesting that the 327/300 for pass. cars is listed as L-74, not L-75. AFAIK there was no difference in the basic engine configuration as built by Flint - just dressed differently like all the ignition shielding for Corvettes with radios.

Duke

[Larry E.]

Re: Base Engine Designation

Interesting that the 327/300 for pass. cars is listed as L-74, not L-75. AFAIK there was no difference in the basic engine configuration as built by Flint - just dressed differently like all the ignition shielding for Corvettes with radios.

Duke

The only difference I know is the Distributor for the Corvette which has the Mechanical Tachometer Provision gearing which the
passenger car does not. Larry