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Hey everyone. Needing some help and I'm sure someone on the forum will have the answer.
When I bought my 1970 LT-1, it did not come with the correct TI distributor nor the correct Holley carb and I am wanting to bring the vehicle back to factory. I know that the carb is a Holley 4555 and the distributor is a Delco-Remy 1111491, however, what would be an appropriate date code for the carb and distributor? I've read that date codes of 6 months from vehicle production date (June 22nd) are normal. What have you guys seen?
Also, are there any ways to tell if a distributor or carb model is a fake? I've seen a few distributors on eBay, however, I know you could just go and buy a serial tag for the distributor.
For the Carb be careful of people selling a 4 digit date code as original as the are not. It is not just the carb center housing numbers also the primary bowl # stamped 6333 secondary 4519 look for any indication of grind out and re-stamp which is done a lot on the 4555 number
The numbers on the 4555 should look very close to this. The date normally is 4 to 6 weeks before cars production. Plus other photos also notice the clutch screws in the accelerator pump these are correct.
THREE-DIGIT DATE CODES
The first digit is last number of the year of production.
9 = 1969
0 = 1970
The second digit is the month of production.
1 = January
2 = February
3 = March
4 = April
5 = May
6 = June
7 = July
8 = August
9 = September
0 = October
A = November
B = December
The third digit is the week of the month of production.
1 through 5
DistributorThe band is red anodized on one side and natural aluminum on the other. This band has been seen stamped with the red side "out" for engines with transistor Ignition and with the red side "in" for point-style distributor through all of 1970 production. The reason we think was to make it easier by sight for works to pick the correct distributor non point type along with the paint daub yours should be orange.
Distributors after mid-1970 have a small hole opposite the tachometer drive gear. Current service replacement housings all have this hole. Earlier distributors did not have it. Yours should have a hole for a June build. Any corvette tach drive distributor of the time period could converted to be a TI. So fakes are easily made.
Awesome information! Thanks, I'll make sure to look for these things you've mentioned.
So, for both the distributor and carburetor, the date code should be within 4 to 6 weeks? That really narrows down the list, don't it?
Thanks again.
That is just what is normally seen but it can be a little earlier or later. The 6 month rule is for judging at the NCRS or
Bloomington so you can have the window at those events and not be penalized. Many times back then parts first in sometimes were not first out.
This photo also shows a little known fact about LT1 carbs. There is a piece of "putty" here covering a very small brass needle screw with a round nose which is actually an adjustable idle air bleed for emissions adjustments. Only OEM factory installed carbs had them. The later service counter carbs did not. This is another way you could spot a possible "fake" carb. They might fake the date, but never the air bleed. Not many people know to look for this. Dunking the carb ruins the putty, and then it looks like this one. Factory ones are so smooth here you almost could be convinced it is a metal divot. So just look at the outside air bleed inside the choke horn, directly opposite this screw, it has a huge orifice on these carbs, not a wire drill size like all the others, because it is no longer the tuning restriction, the screw is. Mine gave me so much fits tuning it I sent it back to Holley in the early 1980s and they rebuilt it and had to look this up on the factory blueprints and even back then the Holley tech was very surprised at this unusual feature. Tip: If you can not get your carb to run right, and your right & left side to run consistent AFRs & temps, at idle to cruise, look here and see if one of these "moved" like mine did. PITA!!!
Distributor and Carburetor Date Code
