What carb should a late '74 258 have???

What Carb number should my mid August 1974 258 have as stock???
Right now it has a 7051SA that comes back as off a '78 F150 300 I-6.

I've seen reference to a #6511S or #7029S ???

I want to be somewhat close to original so I don't want to upgrade to a 2100 or anything like that.

I just want to get the correct # carb to replace this cobbled nightmare

Yes that is a door hinge as an accelerator cable bracket

 

The original was a Carter YF but I have seen Holley single barrel carbs and Rochester Mono-jets used as well.

 

Survey says ...

Carter YF. The most likely number is YF-6432, though a CA car could be YF-6511 or YF-6431. If there's no EGR, it's YF-6432 (but I think all CJs have EGR that year).

 

hate to say it but that looks an awful lot like the carb on my dads 74 motor

 

Well, I just found a 6511S on Ebay.
Brand new old stock still in the box.
Also nabbed a choke heater tube off a 79 DJ5 that looks like it should fit.

I can't wait to start putting more stuff together than I'm taking apart.

 

And a fine carb that is!! haha, I really do love my one barrel carter 258 in the woods just putt-putting around. Its great on fuel. Still getting a 4 barrel though.

 

well here is the one off my 73, looks the same, tried to immage the number, but if it didnt come out its yf6429s , I notice that yours is missing the choke solenoid too. Not sure if this part can be found easily, I was just going to replace mine with a 2100 so I just pulled it off.

 

Does anybody have a linkage laying around that they don't need?
My NOS carb is missing this stuff and the old carb was booty fabbed.

 

The one on the left looks like my old one. Not a bad carb if you don't mind messing with it now and then. I had put a rebuildt YF on it and it came with very few working features. The bolt holes were kinda worn too. I guess some of these old carbs have been rebuildt quite a few times.
Ebay vendor Dynosaurus had some nice rebuildt carbs. They mill them flat, use kits for the newer fuels and press in new throttle valve bushings . Very thorough build and worth the price.

 

Wake up an old thread...

Tim from the looks of what you say 6432 is the number for a 74 258, 3Spd, with EGR, non California. Is this correct?

Next question what is the difference between these carbs? I know some have dashpots and others don't, so that is one thing, but are there other things internally? There is a 6431 for sale on ebay I'm thinking of bidding on but it comes back to a 74 Matador 258 - not even sure what that is. If I bought a CJ5 in 1974 in Ma. with the above configuration is there a chance it could have a 6431?

Thanks for the help.

 

Boy oh boy. I don't think you could know the internal differences without the corporate records. That info may exist somewhere, but it's not in the parts books - they just give a number. I expect that the major differences in the Jeep carburetors will be internal changes to accommodate the proper tuning for emissions. Certainly an EGR carb will have a leaner mixture than a non-EGR carb - that's the purpose of the EGR, to allow a leaner mixture without the otherwise excessively high combustion temperatures.

Let's see what we can infer.

A 6431 is spec'd for a '74 232 or 258 with CA delivery. All '74 CJs came with EGR, so that would not be an issue - indeed, the devices on CA and NW (nation wide) are the same. There are 3 different EGR valves, but no indication of which numbers work for CA or NW. All applications from '74 use the same distributor. So it's likely that the 6431 is just tuned to a stricter emissions standard than the NW carb. There may be some other plumbing changes, but I would presume if you use the 6431, you'd only see a difference at the tailpipe.

No guarantee, but it seems that it'd be ok.

 

Re the 7432 (Jeep PN 321 9503), the book only shows that carb as applying to '74, with no other qualifiers. It lists the YF-7001 (322 3868) as a replacement, used with EGR and AT (so not in a CJ).

I'd be careful to look at the linkage on a carb that came from a car. The AMC Jeep engines were commodity items for that era - no difference between the Jeep and car engines - but there's a possibility that the Carter number could be used on different applications with different external bits. I expect it will be ok, but a confirming picture would make me more comfortable.

 

Thanks for the information Tim.

After thinking about it here is what I came up with. The 6431 has a dashpot and does not have the extra throttle linkage attachment that is required for CJ applications. Those two items are probably what are different between 6431 and 6432. I do not believe that the CJ carb has dashpot for 74 but I am not 100% on that.

I have a 7001 on mine right now but it was reman unit from the PO. No dashpot and no additional CJ linkage (had to make my own).

I have seen other NOS on ebay (can't remember the number) with the linkage and a dashpot - which kind of blows my above dashpot theory. I would like to see a picture of a 6432 because I suspect that is our guy - no dashpot, CJ linkage.

Meanwhile here is the link to the 6431:

http://cgi.ebay.com/ebaymotors/NOS-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

Not sure about the dashpot. I would not worry about it. All it does is slow the descent to idle - this is emissions related typically.

It looks like the part you think is part of the carb (4.070-5), really isn't. The book calls it "Bracket, carburetor lever to accelerator cable" Jeep PN 535 1260. That's not part of the carburetor. So when you look at these various carbs and the part you need is missing, that's not related to the applicability of the carb. An NOS carb isn't going to have it. Nor would a rebuilt carb - a carb rebuilder would have pulled it off, since it's app specific.

IMO there's nothing wrong with a YF-7001 for this app ... should work fine. The seller wants hundreds of dollars for the NOS carb - I'm sure you could get the linkage parts you need from someplace like J&W or Scotty's for much less than that. Scotty's (Fontana, CA) had a whole truck trailer lined with shelves and full of Jeep carburetors last time I was there.