467-Ratman

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!

lbell101

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!

467-Ratman

Thanks Larry for the information! Great work on the 71 Registry.

keytech

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 !

lbell101

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....

467-Ratman

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!

keytech

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!

keytech

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]

lbell101

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.

keytech

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]

clem zahrobsky

4800 is 1970 350 chevy Z-28 with auto

lbell101

Thanks Wayne!

I will do those things!

Rowdy Rat

Clem,

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,

keytech

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!

clem zahrobsky

the holley master catalog list the 4800-1 as a 1970,maybe it could be wrong.

Rowdy Rat

I agree with you on this completely... The carburetors are most likely very similar and from a function standpoint should perform about the same if not identically. My comments were in response to Tom's original post, basically, "What application was it used for?"

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,

467-Ratman

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?

keytech

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.

lbell101

Here's a coincidence:
http://cgi.ebay.com/ebaymotors/aw-cg...840181&r=0&t=0

Rowdy Rat

Not a bad idea at all... The date on the carburetor (late 1978 at the earliest - it's a service replacement) more or less eliminates it as a choice for the "numbers matching" crowd so why not continue to use it?

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,