NCRS Question
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Instructor
Joined: Dec 2007
Posts: 179
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From: Denver Colorado
NCRS Question
I have a '72 LT1 with AC that has 19,000 original miles. Somehow it ended up with a '70 LT1 carburator. Does anyone know if this is correct? If not, what date code carb should I be looking for? The car was built the 1st week of June, 1972.
Drifting
Joined: Jan 2004
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From: Sherman CT
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
St. Jude Donor '24-'25-'26
there are 3 lines on the carb. My carb has these numbers:
The GM part# is the first line on the carb the # is 3999263-GA
The second line is the holley list # mine is 6239-1
The third line is the date code, a 3 digit number, mine is 244. the first digit is the last number or the year of production, the second digit is the month of production, the third digit is the week of the month of production (1 thru 5)
244 would be the 4th week of April, 1972 or approx 12 weeks ahead of my build date
Thats weird that a car with only 19k miles would have to replace the carb, I've heard of stranger things, though.
Love to see some pictures of your car.
Mine is a non A/C with a July 13 build date
Is your carb a list #4555 ?, I think thats what the 70 carbs were, as posted below, could be pretty valuable.
Regards
Roy
Last edited by rvazquez; Sep 8, 2012 at 10:31 PM. Reason: fixed stuff
Team Owner
Joined: Jun 2000
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From: Southbound
Cruise-In II Veteran
You want a Holley model R6239A GM part #3999263 dated within six weeks of the assembly date of your engine. The NCRS will accept a date range up to six months before engine assembly, but the closer the date the better.
Good luck with the hunt.
Good luck with the hunt.
Race Director
Joined: Jul 2001
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There's no notation in the judging manuals about late '72 cars receiving '70 model year carbs. NCRS judges on 'typical of factory production' so this does not fit within that ideal and an appropriate deduction would be taken.
Given that the part number and date must be correct to avoid deduction, the probability of finding such a part is fairly slim and the seller might want an arm and leg for it. Unless you're seriously entering judging, I think I'd save my money for other projects.
Given that the part number and date must be correct to avoid deduction, the probability of finding such a part is fairly slim and the seller might want an arm and leg for it. Unless you're seriously entering judging, I think I'd save my money for other projects.
Race Director
Joined: Jun 2005
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2018 Corvette of Year Finalist
2017 C3 of Year
There's no notation in the judging manuals about late '72 cars receiving '70 model year carbs. NCRS judges on 'typical of factory production' so this does not fit within that ideal and an appropriate deduction would be taken.
Given that the part number and date must be correct to avoid deduction, the probability of finding such a part is fairly slim and the seller might want an arm and leg for it. Unless you're seriously entering judging, I think I'd save my money for other projects.
Given that the part number and date must be correct to avoid deduction, the probability of finding such a part is fairly slim and the seller might want an arm and leg for it. Unless you're seriously entering judging, I think I'd save my money for other projects.
WB
Melting Slicks
Joined: Aug 2001
Posts: 3,050
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From: Wichita KS
There are 38 originality points associated with the carburator, heat insulator, and fasteners (out of 4500 total points). For "Flight" judging the standard is the APPEARANCE of originality. In your case, you would loose originality points for the date not being within 6 months prior to the cars build date.
Depending on what other (if any) differences in appearance there are you might loose only a few points (5-6?). I would get the car judged FIRST, before you start making changes or hunting parts - that will give you a better idea of point gained vs. dollars.
e.g. you will loose 25 points if the cigar lighter does not work - that fix might only cost a dime for a new fuse.
The link below is to the mechanical judging sheets for your car. The NCRS Tech Manual is a good guide.
http://www.ncrs.org/sinor/68-72%20Sc...2%20Mchncl.pdf
Depending on what other (if any) differences in appearance there are you might loose only a few points (5-6?). I would get the car judged FIRST, before you start making changes or hunting parts - that will give you a better idea of point gained vs. dollars.
e.g. you will loose 25 points if the cigar lighter does not work - that fix might only cost a dime for a new fuse.
The link below is to the mechanical judging sheets for your car. The NCRS Tech Manual is a good guide.
http://www.ncrs.org/sinor/68-72%20Sc...2%20Mchncl.pdf
Burning Brakes
Joined: Jul 2010
Posts: 810
Likes: 48
From: West Chester Pennsylvania
There are 38 originality points associated with the carburator, heat insulator, and fasteners (out of 4500 total points). For "Flight" judging the standard is the APPEARANCE of originality. In your case, you would loose originality points for the date not being within 6 months prior to the cars build date.
Depending on what other (if any) differences in appearance there are you might loose only a few points (5-6?). I would get the car judged FIRST, before you start making changes or hunting parts - that will give you a better idea of point gained vs. dollars.
e.g. you will loose 25 points if the cigar lighter does not work - that fix might only cost a dime for a new fuse.
The link below is to the mechanical judging sheets for your car. The NCRS Tech Manual is a good guide.
http://www.ncrs.org/sinor/68-72%20Sc...2%20Mchncl.pdf
Depending on what other (if any) differences in appearance there are you might loose only a few points (5-6?). I would get the car judged FIRST, before you start making changes or hunting parts - that will give you a better idea of point gained vs. dollars.
e.g. you will loose 25 points if the cigar lighter does not work - that fix might only cost a dime for a new fuse.
The link below is to the mechanical judging sheets for your car. The NCRS Tech Manual is a good guide.
http://www.ncrs.org/sinor/68-72%20Sc...2%20Mchncl.pdf
Each 45 points is 1% so you need to plan your restoration strategy and budget.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
If you find that you MUST have the 'correct' carb, put your present carb up for sale as an "Original 1970 LT-1 carb" (if that is the case). When you find that elusive buyer that MUST have the correct carb [like you], that person will pay dearly. And you can then take that ridiculous amount of money and purchase the 'correct' carb that you must have. What a deal!!! (and what a PITA...just to get a carb with a couple of different numbers stamped into it 
)
)
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Hi,
I think many of us have the same problem, but it manifests it's symptoms in different ways.
It might be the search for 1 point out of 10 possible.
It might be the search for a drop of 1/10 of a second, or addition of 1/10 mph.
It might be a search for a polish that makes the finish 1% glossier to 10% of the people looking at the car.
It might be the search for a way to do some repair or maintenance for 1 dollar rather than 10 dollars by finding and buying a locally available part.
It's a car, and it's got us by the nuts 100% of the time!!!!
Maybe?
Regards,
Alan
I think many of us have the same problem, but it manifests it's symptoms in different ways.
It might be the search for 1 point out of 10 possible.
It might be the search for a drop of 1/10 of a second, or addition of 1/10 mph.
It might be a search for a polish that makes the finish 1% glossier to 10% of the people looking at the car.
It might be the search for a way to do some repair or maintenance for 1 dollar rather than 10 dollars by finding and buying a locally available part.
It's a car, and it's got us by the nuts 100% of the time!!!!
Maybe?
Regards,
Alan
