71 LT1 carb/alt dates

[Peter L.]

Hello, I just bought a 71 LT1 and I am trying to verify some dates. The cars body tag is I26 which is April 26, the engine build stamp is V0401CGZ. I am not sure of how to read that date. Since the LT1 wasn't the most common engine, would the carb and alt possibly have an early date since I doubt many batches were run during the year? I believe the alt 1100950 was used on other engines so the date should be close to the cars body tag date, but since the 4801 carb wasn't common, could the carb date proceed the car by 6 months or more? The car is pretty much unmolested with the last owner having the car for 32 yrs. Thanks for your input.

[John C.]

Re: 71 LT1 carb/alt dates

Peter

Your engine assembly date is April 1st (0401). This matches nicely with the body build date. Although LT1 engine cars were less then 10% of 1971 production I wouldn't call them rare. The 6 month rule the NCRS uses for dates is to cover typical factory production. As always, there are exceptions to this rule. What are the dates on your alternator and carb?

John

[Terry M.]

Re: 71 LT1 carb/alt dates

Hello, I just bought a 71 LT1 and I am trying to verify some dates. The cars body tag is I26 which is April 26, the engine build stamp is V0401CGZ. I am not sure of how to read that date. Since the LT1 wasn't the most common engine, would the carb and alt possibly have an early date since I doubt many batches were run during the year? I believe the alt 1100950 was used on other engines so the date should be close to the cars body tag date, but since the 4801 carb wasn't common, could the carb date proceed the car by 6 months or more? The car is pretty much unmolested with the last owner having the car for 32 yrs. Thanks for your input.

You are right about the alternator being used on other Corvette models, so no date exceptions there. Holleys were/are notorious for failures. It is unusual to find an LT1 (of any of the three years) with its original carburetor due to Holley’s propensity to leak both air and fuel.

“The only thing worse than one Holley is three Holleys.” And you can quote me on that.

You will get no exception to the six month date rule-of-thumb for either the alternator or the carburetor. You might want to take a look at the originality points available for the carburetor. Date is 20% of that value. I believe you will find that deduction is not too much in relation to the 4510 total available points.

[Dave S.]

Re: 71 LT1 carb/alt dates

I had a 71 LT-1VIN # 16798 which was a May 1971 build. It was a 21k original mile car that i purchased from the Original owner back in 1998. The car was highly unmolested. When I put it through the NCRS system in 2003 I had this same situation with the carb. date arise. The Holley list #4801 had a date code of 082 which is August, 1970 and had all the characteristics of it being the originak carb. The car ultimately achieved 5 Star Bowtie and Duintov status, (that does not mean the carb was absolutely correct). List #4801 is unique to 71 LT-1 (1970 had List #4555) cars so common sense prevailed and extending the 6 month rule was rationalized. I felt at the time that the early date confirmed a "batch" run as this was a limited production carb. Terry may remember the car as he was the 70/72 team leader at the time. As it relates to the alternator my car had a #950 unit with a 1D7 (April 7, 1971) date.

[Mike E.]

Re: 71 LT1 carb/alt dates

The RESTORER vol 37 no.1 has an article with dating components on 4 very original 71 LT-1s. You might refer to that as well.

[Arne A.]

Re: 71 LT1 carb/alt dates

My 1971 LT-1 (12698) get its original carb replaced after a few months of operation back in 1971 by the original owner. The 4^th owner (1998 to 2005) replaced this carb with a Holley Street Avenger that was on the car when I get it in 2005. Because most other numbers lined up nicely I started a search for a 4801 with a good date code for my car. I was looking for a Jan-Feb 1971 carb but this was very difficult dates to find. All ebay-listings were dated Aug or Sept 1970. After a year or so finally a Feb 1971 carb showed up and its now bolted on my engine. I get the carb restored and the restorer confirmed my experience, all dates except Aug and Sept 1970 are difficult date codes on the 4801.

Yes, it easily leaks and it is feeding the engine with a lot of gas but also gives a lot of power. After replacing the original vacuum can with a B28 and give it manifold vacuum and set the timing to 14 degrees it has a stable idle at 850 and it is possible to take her almost down to 1000 rpm in 4^th and go up with a smooth acceleration (3.70 rear). It has a very strong mid range and from 3500 up it is a race car. Thanks Duke.

This car is a Canada sold roadster, it had owners in Ohio and Tennessee and is now located in Norway.