71 Holley 780 carb numbers?
#1
Burning Brakes
Thread Starter
Member Since: Aug 2001
Location: Bay City MI.
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
71 Holley 780 carb numbers?
Does anyone know the codes for a Holley carb, 780 dual feed style. The numbers on the horn, are: 3989022 list-4800-1 2738. Also in another spot it has this number: 6R 3828. Thanks for the info!
#2
Melting Slicks
Member Since: Nov 2001
Location: Casa Grande AZ
Posts: 2,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (LT1-Tom)
Hi Tom!
Ya - that carb is for a 1971 Corvette LT-1 with automatic transmission according to the data. I'll add carb info to the registry soon!
Ya - that carb is for a 1971 Corvette LT-1 with automatic transmission according to the data. I'll add carb info to the registry soon!
#4
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (LT1-Tom)
The Carb number on a 71 LT-1 should be 3989021. I couldn't find the 3989022 for a 70-72 Vette. 21 ending is in carb for 70 & 71 LT-1, and a 23 ending for a 70 with ECS. The LIST number is a Holley number. The number on the line under this (3rd line) should have a date 3 digit code with a number 9,0,1,2 for the years 69-72. The second digit is the month code with Jan-Dec listed as 1-0,A,B corresponding. The third digit is the week of the month production 1-5. The number you have listed would not be an original Holley carb for an LT-1.
PS- Larry, that better NOT be an automatic in that car. There is no such thing as an automatic LT-1 !
PS- Larry, that better NOT be an automatic in that car. There is no such thing as an automatic LT-1 !
#5
Melting Slicks
Member Since: Nov 2001
Location: Casa Grande AZ
Posts: 2,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (keytech)
Hi keytecch!
Here's the source I used: http://www.quantaproducts.com/carbs/vetcarb.html
I have another print out saying the same thing but the URL is not on it!
Good point about the LT1 with auto... hmmm....
Here's the source I used: http://www.quantaproducts.com/carbs/vetcarb.html
I have another print out saying the same thing but the URL is not on it!
Good point about the LT1 with auto... hmmm....
#6
Burning Brakes
Thread Starter
Member Since: Aug 2001
Location: Bay City MI.
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (lbell101)
The previous owner made the car into a clone of LT-1. The car was orignially a 270hp auto. He then set out to convert it to a 4 speed and got the intake and carb and crane solid lifter cam, and holley 780 carb that was suppose to be for the LT-1. I guess you can't believe everything you are told. The only exception would be on the Corvette Forum!!!!! Thanks to all for the great information, Corvette owners rock!
#7
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (LT1-Tom)
Well, you can't "make" an LT-1. It is or it isn't (only God can make a tree and only Chevrolet can make an LT-1 :) ). But, I wouldn't be too upset. It's never going to be NCRS numbers matching but you do have a car with performance you can enjoy everyday. You get a numbers matching LT-1 and you'd be a little hesitant to take it out and enjoy everyday. This way you can enjoy the ride without worrying about blowing 15K worth of value!
#8
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (lbell101)
Larry-
Well that is interesting but I have my NCRS judging manuals in front of me and they say no "22" at the end. Checked Cars and Parts Chevrolet ID Numbers book and don't have that -22 listed either. Go figure. :)
[Modified by keytech, 9:11 PM 12/9/2001]
Well that is interesting but I have my NCRS judging manuals in front of me and they say no "22" at the end. Checked Cars and Parts Chevrolet ID Numbers book and don't have that -22 listed either. Go figure. :)
[Modified by keytech, 9:11 PM 12/9/2001]
#9
Melting Slicks
Member Since: Nov 2001
Location: Casa Grande AZ
Posts: 2,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (keytech)
Hey Keytech!
I never had any doubt that you were correct!
Data research has been somewhat fustrating as even the GM sources have some errors in them. That's why I don't have the carb numbers (and lots of other stuff) up on the registry yet. I don't feel comfortable putting up the data without some confirming data. I know I'll be leaving that carb number oof my charts!
What's funny is that this erroneous data must have been out there a while. Sounds like whoever bought the carb in the attempt to make a LT1 thought he had the correct part.
My uncles brother has a '71 LT1 that he bought new. As I understand it, it currently has less than 30k miles on it. I think next summer I'll try to get some part numbers and pictures of the details from it. Maybe it still has paint markings and such on it.
I never had any doubt that you were correct!
Data research has been somewhat fustrating as even the GM sources have some errors in them. That's why I don't have the carb numbers (and lots of other stuff) up on the registry yet. I don't feel comfortable putting up the data without some confirming data. I know I'll be leaving that carb number oof my charts!
What's funny is that this erroneous data must have been out there a while. Sounds like whoever bought the carb in the attempt to make a LT1 thought he had the correct part.
My uncles brother has a '71 LT1 that he bought new. As I understand it, it currently has less than 30k miles on it. I think next summer I'll try to get some part numbers and pictures of the details from it. Maybe it still has paint markings and such on it.
#10
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (lbell101)
I would suggest getting the NCRS Corvette Specifications Guide and the NCRS 1970-1972 Corvette Technical Information & Judging Guide. You want detail to the n'th degree that's the place. Many parts suppliers and magazines (heck, Vette Views Fact Book has a picture of an LT-1 engine compartment with a caption saying the carb is an 850cfm) have the drive to get every fact right. Heck they are spread pretty thin getting information for a variety of vehicles where as the NCRS is a group that is fanatical about that very detail and dedicated to researching every nit picky obscure detail and it's history darn near down to the hour it occured in the Design department or on the factory floor! I think it would be a great help for your site. If any question comes up just go to their forum and ask and you will be very surprised at the expertise these folks have and are more than happy to share.
I have a 71 that I have for a driver but I also have a 70 LT-1 that's a restore. You can't even begin to put a price on the info I got from that forum and they will facinate you with the stories behind the info! Good Luck!
Wayne B
PS - contact Juliet here on this forum. She has the 70 registry and can probably give you a lot of help for yours!
[Modified by keytech, 10:22 PM 12/9/2001]
I have a 71 that I have for a driver but I also have a 70 LT-1 that's a restore. You can't even begin to put a price on the info I got from that forum and they will facinate you with the stories behind the info! Good Luck!
Wayne B
PS - contact Juliet here on this forum. She has the 70 registry and can probably give you a lot of help for yours!
[Modified by keytech, 10:22 PM 12/9/2001]
#13
Melting Slicks
Re: 71 Holley 780 carb numbers?
4800 is 1970 350 chevy Z-28 with auto
I'm showing GM part number 3989022, Holley LIST number 4800-1 as the correct part number for a 1971 Z-28 (LT-1) with automatic transmission. The date that Tom listed is for a post 1972 assembled carburetor (three digit Julian date plus last digit of year) so this appears to be a service replacement carb.
1970 applications that used the LT-1 engine and an automatic transmission (Z-28 Camaros and COPO 9010 Novas) used either 3972120/4490 or 3972122/4554 (when ordered with NB2).
Regards,
#14
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (Rowdy Rat)
Well there are many parts that can be crossed between Chevrolets. Several parts on the Z28 are the same as the LT-1 (such as valve covers). But there may be internal diffrences in the two carbs, hence the different number, or as you point out a service replacement. I know the M22 transmission only came on the ZR1 package in the 70 LT-1 but you will find more than then stated 49 produced as that transmission could be bought across the parts counter in a Chevy dealer. In any event. You take that 3989022 and put it on an LT-1 and open the hood in an NCRS or Bloomington Gold competition and you will get a big "WRONG-A-MUNDO cowboy" !
In this case it's a car the guy wants to enjoy everyday and I seriously doubt the two look or perform differently. A good reason to get the Chevy book on cross-matching parts. You don't necessarily have to pay the collector car premium for a part to get a like part and performance. hey, enjoy the ride!
In this case it's a car the guy wants to enjoy everyday and I seriously doubt the two look or perform differently. A good reason to get the Chevy book on cross-matching parts. You don't necessarily have to pay the collector car premium for a part to get a like part and performance. hey, enjoy the ride!
#16
Melting Slicks
Re: 71 Holley 780 carb numbers?
In this case it's a car the guy wants to enjoy everyday and I seriously doubt the two look or perform differently. A good reason to get the Chevy book on cross-matching parts. You don't necessarily have to pay the collector car premium for a part to get a like part and performance. hey, enjoy the ride!
Clem, to be honest, I've never had a 1970 Z-28 or COPO 9010 Nova with an automatic so I don't know for certain. This LIST number could have been a late model year introduction in which case the Holley master catalog could be right on the money. I have a friend who is the keeper of the COPO Nova registry... Perhaps he can fill me in on what carburetor the automatic cars used since the COPO Novas were all late production cars and used the same engine codes as Z-28s (CTB and CTC).
Regards,
#17
Burning Brakes
Thread Starter
Member Since: Aug 2001
Location: Bay City MI.
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (Rowdy Rat)
Hey guys, Thanks for all of the info on the carb. No that we know that it is not for the vette, does anybody think it could have some value to a camaro Z-28 owner?
#18
Racer
Member Since: Oct 2000
Location: Atlanta, GA USA
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (LT1-Tom)
Why not leave it on the Vette? it's a good carb. No reason to change cause of that one digit. Put em side by side and you couldn't tell a bit of difference without a magnifying glass on the number. I'd leave it on.
#19
Melting Slicks
Member Since: Nov 2001
Location: Casa Grande AZ
Posts: 2,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: 71 Holley 780 carb numbers? (keytech)
Here's a coincidence:
http://cgi.ebay.com/ebaymotors/aw-cg...840181&r=0&t=0
http://cgi.ebay.com/ebaymotors/aw-cg...840181&r=0&t=0
#20
Melting Slicks
Re: 71 Holley 780 carb numbers?
Why not leave it on the Vette? it's a good carb. No reason to change cause of that one digit. Put em side by side and you couldn't tell a bit of difference without a magnifying glass on the number. I'd leave it on.
It's a good street carb and probably VERY similar to what came on a 1971 LT-1 Corvette originally. If the numbers game isn't your thing and the car is running well, I'd keep it on the car... Why mess with success? :)
Regards,