John 1971 LT-1

I am restoring a 1971 LT-1 that was pretty complete and wasn't molested to badly. The carb had been replaced in the 1990's and I would like to get a correct Carb for the car. I know the 1971 took the 4801 Holley but I have been searching for a date correct one and am wondering that if this is such an early car in the 1971 production could it have actually had a 1970 Holley carb instead.

I am having the carb that came with the car installed back on the engine but would like to have the correct one for aesthetics and car value. I know the correct carb will not be inexpensive I just want to make sure I get the right one.

MelWff

Considering the compression dropped in 71 and the jet sizes arent the same for 70 and 71, I cannt imagine Chevrolet putting a 70 carb on a 71 since they would be violating emissions regulations.

roadblock69

It very likely would be the same carb. The emissions police of that era determined that the important issue was ppm of pollutants. Thus, the infamous air injectionn reaction pump. By simply adding air to the exhaust stream you lowered the ppm of pollutants. Same total pollutants but less ppm. Government genius at its best!!

MelWff

But Chevrolet had to get the 71 to pass EPA regulations using the 71 carburetor which, again, is jetted leaner than the 70 carburetor and has a different part number.

MidShark

How early is your car? The '71 LT-1 that I had (vin #3081) had August dates most everything, such as 8/25 for the engine assembly, and 085 on the Holley carb, which was the original, correct for a '71 LT-1 carb. There was a strike in September of 1970 that went on for 2 1/2 months, so the car was not assembled until Dec. 4.
I still have a correct '71 LT-1 Holley service replacement carb that I ran on the car while I had the other one restored. Looks brand new yet. PM me if you're interested.

Rich

Solid LT1

70 LT-1 is 11:1 370HP the 71 motor is 330HP 9:1 compression the carbs have different jetting specs. My Holley book is in deep storage right now or I could give you exact specs.

7T1vette

The carb for your car would definitely be for the 1971 model year; but it would have a build date in the July/Aug, 1970 timeframe. The Holley carb would have had a 3989021 part number.

Easy Mike

Yes. 1971 production began in August, 1970. Any cars produced through 12/31/70 would have had 1970 dates.

The correct Holley dated within six weeks prior to the assembly date of your engine would work and closer would be better.

Be aware a strike began about mid September 1970 and continued through nearly the end of November. No October cars were built and not too many November cars. Full production did not resume until December. The assembly date of your engine will tell you whether your car was caught in the strike.

My fiancee's 71 convertible had the same fate as MidShark's car; engine date indicates it would have been assembled very near the begining of the strike. Time Built code ended up as 12/3/70.

Alan 71

Hi John,
I believe that carburetors are one of the items that were produced by the suppliers in batches.
The fewer the number of particular parts that would be needed limited the number of batches made and therefore the dates that would appear on the parts.
So on a early car with a 'relatively' infrequently used part like an LT-! carburetor it would seem that there would be 'relatively' few dates out there. A group of the carbs would have dates that are the same, and then there would be a relatively long period before the next group of carbs were produced with another date.
The opposite of this might be common engine blocks, (like 0010), which might have been cast almost continuously in some periods.
You may be looking for a carb that has just a few dates that would be appropriate for your car.
Regards,
Alan

7T1vette

What none of us know is when production began on the 1971 model year Holley carbs. My 'gut' feeling is that Holley would not have started building those carbs until early July. If that's the case, you won't find dates for '71 LT-1 carbs earlier than that.

I'm sure someone with an early '71 LT-1 can check the date on their carb so this picture can become a bit clearer.