I have purchased a 1976 Corvette that has the correct engine block and transmission installed, but has been modified with some aftermarket parts. I would like to try to get the engine bay back to as close to original as possible. The intake and exhaust manifold numbers should be pretty straight forward. My question is regarding the carburetor. My car was built on Oct 15, 1975; and is an X code (L-82) with the M-21 T-10 4 speed. I don't have the engine date code handy, but can get in a few days if it will help... I'm trying to figure out if I should be looking for a 1975 Rochester 7045211 carb or a 1976 Rochester 17056211 carb... I can't seem to find if production of the "1" series carbs started on Jan 1, 76; or with the 76 model year vehicles. Additionally, what would be the appropriate build date of the carburetor with respect to the engine assembly date? Any help is greatly appreciated!!!

 

Production date codes on components relate to actual calendar date [rather than model year date]. So, you would want a carb built in 1975 between six months prior to the car build (April 15, 1975) to about a week or so ahead of the car's build. I believe that NCRS will accept up to the actual car build date (but, of course, that couldn't actually happen.)

 

Thanks for the reply, 7T1. You have confirmed my suspicions... Do you you (or anyone else) have an idea of what a realistic difference in the carb date code and engine build date should be? I know that the NCRS allows from 6 months prior to build date. But I was hoping that fellow owners could chime in with real-world date codes to help out!!! Thanks!!!

 

Normally, it would be within a month or so. But with the '70 strike (GM stockpiled parts for it, so older parts could be legitimate), it was not a 'normal' situation.

 

Thanks again, 7T1... I've checked ebay, Hemmings, and the parts section here... Looks like I have my work cut out for me on this!

 

The OP has a '76, not a '70.

 

I can't disagree with LT on date code. You're looking for a 7045211 carb and from my observances can run anywhere from 2 weeks to 6 weeks before assembly. So the NCRS 6 month figure is quite generous. Don't be surprised if you find it a challenge to zero on the precise GM number by date code. There is no published sources for the broadcast codes on the carb but than judging is not based on broadcast code. I've collected some info on 75 carbs but not the 211 75 carb.

If you're successful...please pass along the broadcast code. It's look a big black void in the Corvette body of knowledge for carb broadcast codes from 75-77.

 

When (IF?) I find info, I'll try to pass it along... I've only just begun my search, but from the looks of things I wouldn't hold your breath hunt!!!

 

According to this list, the 170 P/N started in 76'

http://www.chevymania.com/partsid/ca...er&model=4-brl

 

Yep, that was my original quandary... Whether the 170's started Jan '76, or with the '76 model year (Aug '75). According to our brethren, my car (Oct '75) needs to have a 7045211 carb...

 

Ok... I've found some info that has cast some doubt on parts of this discussion. I have been looking through carb part numbers and started paying attention to the date codes as compared to the part numbers. One prime example is carb part number 7045184 that is on ebay right now. According to the seller, it carries a date code of 2814. This means that this 1975 model carburetor was built on October 8, 1974. Hmmm... Another example from ebay is carb number 17059553 with a date code of 3418. 1979 model carb built on December 7, 1978. IMHO, this would indicate that there is no 7045211 carb with a date code for my '76; I should be in search of a 17056211 (1976 model) with a date code of around July to Sep of 1975...

 

Some sites do state that the 170 series started in 76.

I was understood that the 170 series started for the 75 production year and my early 75 has a 170 series with this aneroid feature. Don't have numbers handy but here is a quote from the Rochester manual

 

According to the Corvette Restoration Guide and Corvette-World, 1975 model Vettes should have 70452XX carbs and 1976 models should have 17056XXX. My original question was did the 17056XXX carb production start in '75 for the '76 model year, or did they begin on Jan 1 1976... It is beginning to look like the 17056XXX carbs actually started being produced in 1975 to be fitted on '76 model year cars and trucks. If you have an early '75 with a 170+ carb, you may want to check the date code... Now, I could probably understand a very late '75 model that was fitted with a 17056XXX carb from the factory; or possibly a very early '76 with a 70452XX carb. I would think by the time they got to my car (number 7785), GM would have been well into the 17056XXX carbs...
Does anyone on here have an early '76 with the correct carb??? If so, I would sure be interested in the carb number and date code!!!

 

As I said the 170 series was used for the 75 model year and some trucks still got the 70 series up to the late 70's. It was all about emissions for "the engine family", so whatever models GM was pushing for emissions got the 170's.

I try to get a date code from the 75 carbs I have.

 

Nope... the 170 carb started in the '76 model year... And special thanks to 20mercury for clearing this all up for me...
It appears that I am definitely looking for a 17056211 carburetor with a date code of mid to late September, 1975 (probably around September 23), as confirmed by the thoughtful contributions from 20merc's unmolested '76 L-82 4-speed (built about 5 days before mine!)... Thanks for the help here and I hope a few others can find this information useful, as well.
20mercury - this is exactly what I was looking for, thanks again!!!