Help identifying these carbs

[Gregory M.]

What year and engine did these carbs come on?

Front and Rear: 3902353-EU, List 3659, 712

Middle: 3902355-EV, List 3660 (or 3860, 3880...tough to see) 6B3

I believe those dates to be 2nd week of Jan. 1967 and 3rd week of Dec. 1966, but what engine and on what year/car would they be considered correct? Thanks for saving me a lot of time...

GM

[John C.]

Re: Help identifying these carbs

Greg

The center carb is correct for either a 67 400hp or 435hp engine with a manual transmission. The list is 3660.

The end carbs were used on all 67-69 400hp and 435hp engines with either manual or automatic transmissions.

Your interpretation of the date codes are correct.

John

[Gregory M.]

Re: Help identifying these carbs

John,

Thanks so much...I still have a few questions:

1) Do you know the time frame these carbs would be considered "correct". In other words, by NCRS judging standards, does the six month rule apply making these "correct" for a car assembled from about February 1967 to about August 67?

2) Are the part and list numbers on 400/435 carbs the same as above for 1968?

3) There is NO way these would be considered correct for a July 1968 assembled vehicle, right? They came with that car when I purchased it and I am considering flight judging...if the part number and list number are the same for 1968, how much of a deduction would I lose for improper date codes?

GM

[Gregory M.]

Re: Help identifying these carbs

John,

I just re-read your post and realized that the part and list numbers for the end carbs are correct for a 67-69 so correct for a 1968 435 car, only the dates are the issue...how much of a point deduction would I receive for that?

Lastly, do you know the correct part and list numbers for a 1968 435 car with 4 speed? Thanks again.

GM

[John C.]

Re: Help identifying these carbs

Greg

The general 6 month rule would apply to the carbs as well. I can't imagine any judge accepting the large date spread you have as orginal. I'm not an expert judge so some one may correct me but you would most likely receive a 20% deduct on the end carbs for orginality. For the center carb it would be higher as you also have the wrong configuration.

On the bright side, with the interest in 67 tri-powers so high you do have a very valuable set of matched carbs.

I will post the correct numbers for a 68 center carb latter today if some one doesn't step in before me with the info.

John

[Jack H.]

In some cases...

relatively low production 'exotic' carb setups were ordered in 'batches' for economic considerations and the 6-month rule may NOT apply. But, if that's the case, your copy of the applicable Judging Guide ought to provide guidance. Look there for your answer and if there is no specific guidance, then consider the 6-month rule applies....

[John C.]

Re: Help identifying these carbs

Greg

For a 68 435hp car with a manual transmission two possible part and list numbers are correct.

The first design is 3925517ev list 4055

The second design is 3940929ev list 4055-1

The only difference between the designs I see on my spec sheet is the second design has an idle vent and the first does not.

I don't know when the change design took place but my 68 435hp car has a 4055-1 list carb with a March production date.

John

[Gregory M.]

Re: Help identifying these carbs

John,

Thanks for the info...I have to order a judging manual in order to figure out if I should replace just the center carb or the set...I am leaniing toward the latter...

GM

[Gregory M.]

Re: Help identifying these carbs

"I don't know when the change design took place but my 68 435hp car has a 4055-1 list carb with a March production date"

John, can you please provide date code on carbs and vehicle build date...any reason to beleive they are origianl carbs? Thanks again.

GM

[John C.]

Re: Help identifying these carbs

Greg

When I bought the car the end carbs appeared to be orginal but the center carb was a later service replacement. The end carbs both had a date of the the 3 week in March 1968. I bought a matching date replacement center carb to go with the ends. I was lucky and found one that is dated only a week before the centers. It is a 4055-1 list.

The car itself was built April 18th.

John